BIOLOGY

TABLE OF CONTENT
Introduction ………………………………………………………………………………………...
Acknowledgement.…………………………………………………………………………………
Examination 1 ……………………………………………………………………………………...
Examination 2 ……………………………………………………………………………………...
Examination 3 ……………………………………………………………………………………...
Examination 4 ……………………………………………………………………………………...
Examination 5 ……………………………………………………………………………………...
Examination 6 ……………………………………………………………………………………...
Examination 7 ……………………………………………………………………………………...
Examination 8 ……………………………………………………………………………………..
Examination 9 ……………………………………………………………………………………..
Examination 10..…………………………………………………………………………………..
Examination 11..………………………………………………………………………… ……….
Examination 12..………………………………………………………………………… ………..
Answers of examination 1 .………………………………………………………………………..
Answers of examination 2 .………………………………………………………………………..
Answers of examination 3 .…………………………………………………………… ………….
Answers of examination 4 .…………………………………………………………… ………….
Answers of examination 5 .…………………………………………………………… …………..
Answers of examination 6 .…………………………………………………………… …………..
Answers of examination 7 .…………………………………………………………… …………
Answers of examination 8 .…………………………………………………………… …………
Answers of examination 9 .…………………………………………………………… …………
Answers of examination 10.…………………………………………………………… …………
Answers of examination 11.…………………………………………………………… …………
Answers of examination 12.…………………………………………………………… ………….
 THE UNITED REPUBLIC OF TANZANIA
PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT
FORM FOUR EXAMINATION - SERIES 01

BIOLOGY- 2022
INSTRUCTIONS TIME: 03HRS

1. This paper consists of three sections, A, B, and C.

2. Answer all questions in section A and B, and two questions in section c. Question
number 13 is compulsory.
3. All drawings must be in pencil and writings must be in black or blue pen.
4. Cellular phones, smart watches and all unrequired materials are not allowed in
examination room.

SECTION A (15 MARKS)

1. In question i – x select the best answer among the given alternatives and write its letter in the
space provided.
(i) Students at Kazamwendo secondary were educated about risk behaviors that must be
abstained. Among the behaviors to be abstained were;
A. Alcoholism and patience
B. Unsafe sexual intercourse and exercising
C. Raping and alcoholism
D. Sharing books during studying and exercising

(ii) In performing food test experiment, after mixing food sample solution, sodium hydroxide
and copper II sulphate, the color of the mixture turned to purple. This implies;
A. protein present
B. starch present
C. lipids present
D. reducing sugar present

(iii) When the sugar is completely oxidized in the cell, it is called;

A. aerobic respiration
B. breathing
C. anaerobic respiration
d. respiration
(iv) In a garden of peas, a gardener observed the seedlings with its cotyledons on the ground.
Those seedlings undergo;
A. hypogeal germination
B. epigeal germination
C. cotyledon germination
D. positive growth
(v) In order to avoid dislocation during movement, two bones are held together by strong tissues
which are known as;
A. muscles
B. tendons
C. cartilage
D. ligaments

(vi) Among the given alternatives one is not correct about growth in mammals;
A. it is irreversible
B. involves increase in complexity
C. broken organs can regenerate
D. enables mammals to adapt their environment

(vii) A person who suffers from night blindness is likely to be lacking………….

A. vitamin C
B. vitamin A
C. vitamin B12
D. vitamin D

(viii) Chickens and dogs have the ability to maintain constantly body temperature. They are
described as
A. homeotherms
B. poikilotherms
C. ectotherms
D. regulators

(ix) When students were doing private study at night, light went off suddenly. Which of the
following change occurred in the eyes of the students?
A. the lens become thicker
B. the eye opened wider
C. the iris enlarged
D. the pupil enlarged
(x) During any mitotic division …………… number of cells is expected to be produced
A. four
B. one
C. two
D. three
2. Match the items in list A with their corresponding in list B by writing the letter of correct
answer against the number of item.
LIST A LIST B
(i) nucleus A: site for respiration
(ii) mitochondria B: site for transpiration
(iii) chloroplast C: place where cell organelles are suspended
(iv) cell membrane D: controls all activities of the cell
(v) cytoplasm E: site for photosynthesis
F: allows some substances to enter the cell
G: allows all substances to enter the cell

SECTION B (60 MARKS)

3. Some chemicals used in biological experiments are very dangerous and harmful. In what ways
the following substances are harmful?
(i) Biohazards
(ii) Radioactive substances
(iii) Toxic substances
(iv) Corrosive substances
(v) Highly flammable substances
(vi) Oxidizing agents

4. Around the school farm there were two kinds of flowers classified as group A and group B.
Group A flowers attract insects so much and group B were not. The two kinds undergo different
type of pollination.
(a) Identify the type of pollination favorable for group A and B
(b) Differentiate flowers in group A from those in group B. (4 points)

5. At a certain birthday party, people were drinking soda and eating cakes. Expectedly, their blood
sugar levels were high. Explain the mechanisms taken by their bodies to regulate high and low
blood sugar levels.

6. In order for organism to grow well, there must be a particular kind of cell division
(a) Identify and give meaning of the kind of cell division responsible for growth
(b) How is the kind in 6 (a) above significant? 4 points.

7. For gaseous exchange to be effective, respiratory surfaces must possess some special features
to make the process successful. Identify any four adaptive features of the respiratory surface that
enable gaseous exchange to be effective.
8. During classification period, form three students classified maize and beans in two separate
classes.
(a) Identify the classes maize and beans were classified to.
(b) Point out four benefits of the plants above
9. When form one pupils visited biology laboratory, they found out different equipment which
were not familiar to them. As a form four student explain to them the role of the following
equipment
(i) Mortar and pestle
(ii) Glass watch
(iii) Hand lens
(iv) Measuring cylinder
(v) Test tube
(vi) Test tube holder

10. Blood circulation is essential for any mammal in everyday life. How is blood circulation
important to a mammal body? (04 points).

11. in a certain ecosystem there were the following organisms; lizard, grasshopper, hibiscus plants,
mushrooms, frog, butterfly and bee.
(a) Construct a food web using those organisms.
(b) From the food web identify
(i) Secondary consumers
(ii) Decomposers

12. How the study of biology is important in our daily life? (4points)

SECTION C (25 MARKS)

Answer two questions from this section. Question 13 is compulsory.

13. In a certain village, people were suffering much from waterborne diseases which affected their
digestive systems. As a biologist you are required to educate them on the diseases basing on the
following;
(i) Meaning of waterborne diseases
(ii) Two examples of waterborne diseases affecting the digestive system
(iii) Common symptoms of the diseases
(iv) Preventive and control measures of the diseases.

14. Explain three advantages and two disadvantages of transpiration process in plants.

15. As classification is one of the topics of interest in Biology, explain it relying on the following
(i) Meaning
(ii) Types
(iii) Importance.
 THE UNITED REPUBLIC OF TANZANIA
PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT
FORM FOUR EXAMINATION - SERIES 02
BIOLOGY- 2022
TIME: 3:00 Hours

Instructions
1. This paper consists of sections A, B and C with a total of fifteen (15) questions.
2. Answer all questions in section A and B and any two (2) questions from section C, of
which question 13 is compulsory.
3. Section A carries fifteen (15) marks, section B sixty (60) marks and section C carries
twenty five (25) marks.
4. All writing should be in blue or black pen, except for diagrams that must be drawn in
pencil.
5. Cellular phones and any other unauthorized materials are not allowed in the examination
room.

SECTION A (15 marks)

Answer all questions in this section.
1. For each of the items (i)-(x), choose the correct answer from among the given alternatives and
write its letter beside the item number in the answer sheet provided.
(i) Which among the following is not an infection and disease of the respiratory system?
A. Asthma B .Bronchitis C. Pneumonia D. Emphysema E. Luekaemia.
(ii) What among of the following conditions or factors can be changed or change in an
Experiment?
A. Problems B. Hypothesis C. Conclusion D. Variables E. Observations
(iii) One of the following is the similarity between Division Coniferophyta and Division
Angiospermophyta
A. They reproduce sexually by seeds C .They have cones
B. They are wind pollinated D. They have seeds with cotyledons
E. They produce flowers
(iv)Eating a lot then forcefully removing the food from the body immediately is known as?
A. Obesity B Marasmus C Bulimia nervosa D Kwashakor E Rickets
(v) Magesa started salivating as he saw peeled half ripe mango with topping of red chilli
powder. What part of the brain is concerned with Magesa’s salivation.

A Hypothalamus B. Medulla oblongata C cerebellum D Cerebrum

E. Cerebral hemisphere
 (vi) The outermost floral part of a flower is called
A Petal B Sepal C Stamen D Receptacle E Stalk
(vii) When giving First Aid to a snakebite victim you should not
A Cut the wound B Calm them down C Remove jewellery from the bitten limb
(D) Lower the bitten area. (E) Wash the wound.
(viii) Which theory suggests that life arose from the evolution of simple organic
molecules into more complex ones and their ultimate evolution into cells.
(A) Spontaneous generation theory (B) Cosmozian theory
(C) Special creation theory (D) Organic evolution theor
(E) Steady state theory
(ix) Juma has blood group O. therefore Juma has an antigen
(A) B (B) A and B (C) A (D) He has no antigen (E) He has no antibody
(x) The following are typical parts of eukaryotic cell except.
(A) Cytoplasm (B) Cell membrane (C) Nucleus (D) Cilia (E) Mitochondria.

2. Match the items in List A with the responses in List B by writing the letter of the correct
response beside the item number in the answer sheet provided:

LIST A LIST B
i.Allows air to get in and out of the middle ear A. Pinna
ii.Transmit vibrations of sound from the eardrum to the oval B. Auditory canal
window. C. Eardrum
iii.Vibrates and transmits the sound vibrations to the ear D. Ossicles
ossicles. E. Eustachian
iv.Collects, concentrates and directs sound waves into the F. Cochlea
auditory canal. G. Semi circular canals
v.Directs sound waves to the eardrum, H. Sebum

SECTION B (60 Marks)

Answer all questions in this section
3. (a)Give the meaning of the following terms as used in Biology
i) Osmosis
ii) Double blood circulation
b) i) State any two components of the vascular system
ii) Name two features of the red blood cells
4(a) i) what do you understand by term respiration?
ii) State two types of respiration
b) Outline any four (4) adaptations of the respiratory surfaces
5(a) State any four (4) laboratory safety rules
b) Briefly explain why we need laboratory rules. ( any two points)

6. Study carefully the following food web taken from a part of Serengeti National park, then
answer the questions that follow:

Bacteria

Hyena

Lion Gazelle

Zebra

Grass Shrubs

(a) What will happen if bacteria will be eliminated from the food web?
(b) Name the organisms from the food web which form the third trophic level
(c) Point out the organisms which form the group of secondary consumers.
(d) Extract four food chains from the above food web.
7. (a) (i) Define the term mitosis

(ii) Outline the significance of mitosis to organisms

(b) Define the following terms and give an example of an organism where each takes place
(i) Complete metamorphosis
(ii) Incomplete metemorphosis
(iii) Ecdysis
8. (a) A pure line pea plant which produces axial flowers was selfed with a pure line plant
which produces terminal flowers. All the F1 plants produced had axial flowers. When the
axial flowers were selfed they gave out 312 plants with axial flowers and 104 plants with
terminal flowers.
(i) Which character was dominant? Give reason(s)
 (ii) Show how the axial flowered plants were obtained in the first cross
(iii) Show how the two phenotype of plants were obtained in the second cross
(iv) In F2 offspring how many were homozygous axial flowered?
(b) What is incomplete dominance?
9. a) Define the term Organic Evolution
b) List down any three (3) theories of origin of life.
c) Name two theories that support Organic Evolution

10. (a) List down the major groups of living things

b) Identify the group in which each of the following organisms belongs;
i) Mushroom ii) bed bug iii) liverwort iv) Earthworm v) Amoeba (vi) Bacteria
vii. Maize

11. (a) Give four ways which people can use to minimize complications of the pregnancies.
(b) Mention two causes of infertility in human.
12. (a) What is homeostasis?
(b) Briefly explain how vertebrates overcome the problem of being overheated.
SECTION C (25 marks)
Answer two (2) from this section, question 13 is compulsory.
13. As a Health Prefect, prepare a morning speech to address to your fellow students at the parade,
about how to keep themselves and the environment clean. Considering the following guidelines;
• Meaning of personal hygiene
• Importance of personal hygiene (any two)
• Principles of personal hygiene (any six)
• Items necessary for personal hygiene (any eight)

14. With the aid of a diagram, identify and label the main parts of the alimentary canal.
15. a) A form two students wanted to test proteins, lipids and starch present in a given food sample
solution, but they did not know how to go about. As a form four student, help these students how to
carry out this experiment by filling the necessary information in a table form as shown below:

Food tested Procedure Observation Inference

b) In addition to the food substances named in 15 (a), list down the missing components for a
balanced diet.
 THE UNITED REPUBLIC OF TANZANIA
PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT
FORM FOUR EXAMINATION - SERIES 03
BIOLOGY- 2022
TIME: 3:00 Hours

INSTRUCTIONS
1) This paper consists of section A, B and C
2) Answer all questions in section A and B and only Two (2) questions from section C
3) All writtings should be in blue or black Ink pen excepts for diagrams that must be drawn
in a pencil
4) Cellular phones and any unauthorized materials are not allowed in the examination room
5) Write your Examination number (index number) on every page of your answers booklets
provided
SECTION A {15 Marks}
Answer all questions in this section
1. For each of the following items (i – x) choose the correct answer from among the given
alternatives and write its letter besides the item number in the answer booklet(s)
provided.
i. Which of the following diet should be added to the diet of lactating mother:
A. Groundnuts C. Cassava
B. Fish D. Orange

ii. The functional unit of the Kidney is:

A. Ureter C. Urinary blader
B. Glomerulus D. Nephrone

iii. A communicable disease which effects large number of people in a short period
of time in a given locality is referred as:
A. Epidemic C. Sporadic
B. Endemic D. Pandemic

iv. The movement of bulk fluid materials along a vessel or tube is termed as;
A. Osmosis
B. Diffusion
C. Mass flow
D. Transport
 v. A respiratory surface in fish is called
A. Gills
B. Fins
C. Operculum
D. Spiracle

vi. The by-products in photosynthesis process are referred as

A. Oxygen and water
B. Carbohydrate and carbondioxide
C. Carbohydrate and water
D. Carbondioxide and oxygen

vii. A term describes the organisms with similar nutritional habit is known as
A. Community
B. Food chain
C. Trophic level
D. Food web

viii. A structure which encloses and protects the inner parts of a cell is called
A. Cell wall
B. Cell membrane
C. Nucleus
D. Chloroplasts
a
ix. A blood vessel which conveys oxygenated blood towards the heart is called:
A. Artery
B. Vein
C. Pulmonary artery
D. Pulmonary vein
x. A carpel of a flower consists of:
A. Anther and style
B. Style, stigma and ovary
C. Stigma and ovary
D. Style and ovary

2. Match the items in List A by choosing the correct answer form List B and write by
writing the corresponding letter in box provided
LIST A LIST B
i. Growth which occurs when the rate of cell A. Apical meristem
increase is higher than the cell loss B. Lateral meristem
ii. The type for cell division which results into C. Epigeal germination
two daughter cells D. Hypogeal germination
iii. The kind of seed germination in which the E. Meiosis
cotyledons emerge from the ground F. Mitosis
iv. The ability of seed to germinate G. Seed dormancy
v. Cause the increase in length and height of H. Seed viability
roots and shoots I. Positive growth
J. Negative growth
 SECTION B (60 Marks)
Answer all questions
3. (a) Define the term “First Aid” and “First Aid Kit”

(b) i/ List four importance of first Aid

ii/ Briefly explain how to render first aid to a snake biten victim (four points)

4. (a) What do you understand by the term “Gaseous Exchange”

(b) i/ List organs responsible for gaseous exchange in the following organisms;

S/N Organism Respiratory organ

i. Amoeba
ii. Grasshopper
iii. Toad pole
iv. Tilapia
v. Plant

ii/ Explain three factors affecting the rate of respiration

5. (a) i/ Define the term Excretion

ii/ List three importance of excretion in mammals

(b) Explain why form three students at KIGHARE SECONDARY SCHOOL there in
Usangi they have frequently Urination during morning class session.

6. (a) Differentiate between Meiosis from Mitosis. (Any two points)

(b) Briefly explain the terms “Responsible sexual behaviour” and “Irresponsible
sexual beahviour” with any two example for each

7. (a) Define the following biological terms

i. Reflex action
ii. Reflex arc

(b) Use the flow diagram to describe neurotic pathway of reflex action

8. (a) i/ Give the meaning of term “Waste”

ii/ State three basic principle of waste disposal

(b) Outline four effects of poor waste disposal

 9. 400 rose plants with red petals with some white spots were crossed with same plants
species having red petals with some white spots. A first filial generation led the
following phenotypic proportions, 290 plants with red petals, 110 plants with red
petals with some spots.
i. Use property defined genetic symbols to show all crosses that lead to
the following of above plants and write simplified ration for the plants
ii. What is the genotypic ratio of first filial generation
10. (a) List five general characteristics of Kingdom Animalia

(b) Place the following Organisms to their respective classes

Organism Class
i. Earthworm ……………………………………………………
ii. Bean plant ……………………………………………………
iii. Cockroach ……………………………………………………
iv. Millipede ……………………………………………………
v. Ostrich ……………………………………………………
vi. Rat ……………………………………………………
vii. Tapeworm
……………………………………………………

11. Explain the Mechanism of blood sugar regulation in mammals

12. (a) Differentiate between Digestion and Egestion

(b) Explain how ileum in human alimentary canal is adapted to its mode of function
(five points)

SECTION C (25 Marks)

Answer two questions form this section. Question 13 is compulsory.
13. Majority of people believe that all bacteria are harmful organisms. As a biologist
explain how bacteria are beneficial and harm to human beings (15 marks)

14. Living organisms are reproducing day after day but it seems the population of various
organisms remains constant. By using ideas of Darwin theory. Discuss (10 marks)

15. Write an essay about COVID – 19 using the following guidelines

- Causes
- Mode of transmission
- Signs and symptoms
- Effects
- Prevention measures
******************************************************************************
 THE UNITED REPUBLIC OF TANZANIA
PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT
FORM FOUR EXAMINATION - SERIES 04
BIOLOGY- 2022
TIME: 3:00 Hours

INSTRUCTIONS
1. This paper consists of section A, B and C with total of fifteen (15) questions.
2. Answer all questions in section A, B and two (2) questions from section C of which question
13 is compulsory.
3. All writings should be in blue or black pen, except for diagrams that must be in pencil.
4. Be neat and maintain good hand writing.

SECTION A (15 Marks) Answer all questions from this section

1. For each of the item (i) – (x) choose the correct answer from among the given alternatives
and write its letter beside the item number in the answer sheet provided.
i. strong tissue that holds muscles to bones at the joints is
A. Ligament B. Cartilage C. Connective tissue D. Tendons

ii. Which of the following organisms belong to phylum ascomycota

A. Bread mould C. Mushroom
B. Yeast D. Toad stool
iii. By which process does carbon dioxide pass from blood to alveoli of the lungs
A. Osmosis B . Diffusion C. Transpiration D. Respiration
iv. In which category the malpighian layer of mammalian skin is plastic?
A. System B. Cell C. Tissue D. Organ
v. After period of vigorous activity you would except blood leaving a muscle to have
A. More carbon dioxide, more oxygen and more glucose
B. Less carbon dioxide, less oxygen and less glucose
C. More carbon dioxide, less oxygen and less glucose
D. More carbon dioxide, less oxygen and more glucose
vi. Predict what will happen if the plant lack nitrogen
A. Leaves will turn to yellow
B. Leaves will turn to blue
C. Leaves will turn to purple
D. Leaves will turn to brown
vii. The statement that will summarize what a scientist has learnt from the experiment
A. Problem identification C. Hypothesis
B. Conclusion D. Data interpretation
viii. A part of microscope which allow the observer to move the microscope tube up
and down by tiny amounts to change the focus and see specimen clearly
A. Rotating nosepiece C. Focusing knobs
B. Eye piece lens D. Objective lens
ix. Calculate the data of ovulation in a menstrual cycle of 28 days if menstruation occurs
on day 9th to 13th of a month.

A. 18th C. 28th

B. 20th D. 22nd
x. A term which best described a condition of a plant cell that has lost too much water is
A. Haemolysis C. Crenation
B. Turgidity D. Plasmolysis
2. Match the responses in list B with the phrases in list A by writing the letter of the correct
responses from list B beside the item number.

LIST A LIST B
i. Renal vein A. Tube that carries urine from the kidney to the bladder
ii. Renal artery B. Tube that carry urine from the bladder to the outside of the body.
C. Stores the urine temporary
iii. Ureter D. Collects urine from all the collecting ducts
E. Take blood away from the kidney
iv. Urethra F. Brings blood containing waste products to the kidney.
v. Urinary bladder

SECTION B (60 Marks)

Answer all questions in this section

3. (a) Give the meaning of the term “laboratory”

(b) With the aid of diagram, briefly describe the following warning signs.
(i) Biohazard

(ii) Toxic
(iii) Flammable
 4. Study the food web and answer the questions which follow

a) From the diagram name (i) two primary consumer and (ii) Secondary consumer
b) Construct, using the food web above, one food chain, with four links’
c) Explain why every food chain must begin with green plant.
d) If all the owls were killed, what would happen to the size of the populations of
earthworms.

5. (a) Give one function for each component found in gastric juice
(b) How does ileum adapted to its role (02 points)
6. (a) Give the name of muscles which are found above and below humurus.
(b) Explain what happen to the muscles when

i. The arm is bending

ii. The arm is straight
(c) what are the adaptations of the muscle to its functions.
7. (a) Differentiate between simple reflex action and conditioned reflex action. (4 points)
(b) Why we cannot “test” food well when suffering from cold?
8. Ngosha on his way to school came across a lion on the path coming right towards him. In
no time she found herself up a tree.
i. What give him the ability to climb the three so quickly?
ii. Identify the different process that went on in his body during this incidence. (only3)
9. (a) What is “germination” and A seed”
 (b) There how many types of germination and what are they?
(c) What are the changes which occurs during seed germination.
10.(a) Use the word “hormozygous”, “heterozygous”, “dormant” and “recessive”
(where suitable) to describe the following gene combination
(i) Bb (ii) BB (iii) bb
(b) A married couple has four girls children but no boys. Does this mean that the husband
produces x – chromosomes only?. Show how the father is the determinant of the sex of the child.
11.(a) What is binomial nomenclature
(b) Give any three (3) rules followed in naming organisms scientifically. (c) List two (2)
advantages of giving scientific names to an organism.
12.Briefly explain the mechanism that helps mammals to control their body temperature in
their environment. (4 points)

SECTION C (25 marks)

Answer two (2) questions from this section. Question 13 is compulsory.
13.Why are mothers advised to breast feed their babies instead of using bottle feeding or cup
feeding from powder or liquid milk? (6 points)
14.Briefly explain the mechanism of breathing in human beings.
15.(a) Give the long term of STLs, STDs, HIV and AIDS.
(b) Explain the risky situation, behaviour and practice which lead to the disease listed
above.

****************************************************************************
 THE UNITED REPUBLIC OF TANZANIA
PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT
FORM FOUR EXAMINATION - SERIES 05
BIOLOGY- 2022
TIME: 3:00 Hours

INSTRUCTIONS

1. This paper consists of section A, B and C with total of fifteen (15) questions
2. Answer all questions in Section A and B and TWO (2) questions from section C
3. Except for diagrams that must be drawn in pencil, all your work must be neatly written in blue or
black ink
4. Write your Name on every page of your answer booklet(s)

SECTION A (15 Marks)

Answer all questions in this section

1. For each of the items (i)-(x), choose the correct answer among the given alternatives and write its
letter beside the item number in the answer booklet provided
(i) Which is NOT a type of sense?
(A) Taste (B) Smell (C) Testes (D) Touch (E) Sound
(ii) ………… waste is in the form of liquid or in watery state
(A) Sludge Waste (B) Urine (C) Liquid Waste (D) Gaseous Waste
(E) Mud Water
(iii) The villi in the small intestine ………………
(A) Increase surface area for digestion (B) Increase surface area for absorption of food nutrients
(C) Have no function (D)Secrete digestive enzymes (E)Reduce diffusion distance of food nutrients

(iv) A blood group B― Patient hospitalized for blood deficiency can only receive blood from two
possible donors
(A) 𝐵− or 𝑂+ (B) 𝐴− or 𝑂+ (C) 𝐵− 𝑜𝑟 𝑂 −
(D) 𝐵+ or 𝐵− (E) 𝐵− or 𝐴𝐵+
(v) Before birth bone are made mostly of cartilage whose cells absorb ……… after birth to produce bones
(A) Potassium (B) Calcium (C) Sodium (D) Magnesium (E) Iron
(vi) Excess amino acids in the body are broken down to form urea in the …………
(A) Pancreas (B) Spleen (C) Liver (D) Ileum (E) Kidney
(vii) A mammalian body temperature ……………
(A) Is under control of the heart (B) Change with environmental temperature
(C)Remain fairly constant (D) Is about 37 degrees Fahrenheit
(E)Is under control of environment
 (viii) …………… is only allowed for married adults
(A) Anal Intercourse (B) Homosexuality (C) Prostitution
(D) Bestiality (E) Sexual (Vaginal) Intercourse
(ix) Which of the following traits cannot be inherited:
(A) Eye Colour (B) Dimples (C) Body Scars (D) Height (E) Body Colour
(x) What is the name given to the crossing of F1 generation/Hybrid to one of its parents?
(A) Reciprocal Cross (B) Test Cross (C) Back Cross (D) Monohybrid Cross (E) Genetic Cross
2. Match the phrases in LIST A with the responses in LIST B by writing the letter of the correct
response from LIST B beside the item number of LIST A in your answer booklet.

LIST A LIST B

i. Absorption of water occur here A. Diabetes insipidus

ii. The process by which urine is formed B. Diabetes mellitus
iii. Plant waste product used to make malaria drugs C. Hibernation
iv. Behavioral patterns where organism go to deep D. Aestivation
sleep E. Distal convoluted tubule
v. Diabetes characterized by sweet urine F. Loop of henle
G. Morphine
H. Quinine
I. Ultra filtration
J. Decantation

SECTION B 60 Marks

3. (a) define Microscope

(b) State the functions of the following parts of microscope
(i) Stage (ii) Diaphragm (iii) Stage clip (iv) Body tube
(v) Mirror

4. (a) Name the cell organelles that perform the following functions:
(i) Synthesis protein
(ii) Control vital processes in the cell
(iii) Control materials entering and living the cell
(iv) Site for respiration
(b) “Life is only possible in a cell with no nucleus” Account for this statement

5. (a) With vivid example, explain three (3) basic principles of waste disposal
(b) How can you maintain good manner when you’re invited for dinner at your
neighbour’s house?

6. (a) state the part of the human digestive system which depends on external
Secretion for digestion and identify three food nutrient digested in this part
(b) Name food nutrient whose digestion is highly affected when human stomach was
removed, state enzyme involved and condition required in the digestion of the food
nutrient named

7. (a) (i) Define the term Oxygen Dept.

(ii) Write a word equation for the anaerobic respiration of glucose in:
➢ Muscle Cells
➢ Bean Plant
 (b) A person who was living at sea level had 5.1 X 1012 red blood cells in every litre of
blood. This person moved to live in the highlands after some times his/her blood had 6.4
X 1012 red blood cells per litre of blood. Explain the advantage of these changes

8. (a) explain the following

(i) Why are many white blood cells found in the region of wound
infected with bacteria
(ii) Why matured red blood cells lacks nucleus
(iii) Why veins had valves at a regular interval
(iv) How water in the soil enters the root hair cells of a plant

(b) Mention three factors that enable arteries to transport blood at great distance

9. (a) (i) Define the term reflex action

(ii) Arrange the following components of reflex arc in a correct order
• Intermediate neuron
• Motor neuron
• Receptor
• Sensory neuron
• Effector organs
(b) State the hormone which is being produced in excess in the following conditions
i. Elevated Basal Metabolic Rate (BMR)
ii. Gigantism
iii. Low blood sugar levels
iv. In reabsorption of sodium in loop of henle
v. In contraction of uterus

10. (a) Briefly explain the following terms

(i) Incest
(ii) Homosexuality
(iii) Prostitution
(iv) Masturbation
(b) Differentiate identical twins from Fraternal twins

11. (a) Briefly explain why during adolescences stage the rate of growth is rapid?
(b) Draw the diagram of sigmoid growth curve, label the four significant phases

12. (a) State mendelian 1st law of inheritance

(b) One family was quarreling due to a baby girl being an albino while neither of the couple
was an albino. The father of the child was telling his wife that she was responsible for the child
being an albino. By using genetic diagrams that are well illustrated, show how the two parents
each was responsible for albino daughter and not the mother only. Using capital letter “A” as the
dominant gene
SECTION C (25 Marks)

Answer TWO (2) questions from this section and question number 13 is compulsory

13. Cholera is a serious disease that affects large number of people within a short period of
time. Write an essay on cholera using the following headings:
(i) Causative agent (ii) Mode of transmission (iii) Symptoms (iv) Effects (v) Preventive
measures (vi) Treatment
14. With vivid examples, discuss five (5) ways through which communicable diseases are
transmitted from one person to another
15. Describe how oxygen from the atmosphere gets its way to the liver tissues

***********************************************************************************
 THE UNITED REPUBLIC OF TANZANIA
PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT
FORM FOUR EXAMINATION - SERIES 06
BIOLOGY- 2022
TIME: 3:00 Hours

INSTRUCTIONS

1. This paper consists of sections A, B and C with a total of 15 questions.

2. Answer all questions in sections A and B and TWO questions from section C
in which question 13 is compulsory
3. All writing should be in blue or black pen, except for diagrams which must be
inpencil
4. Cellular phones and any unauthorized materials are not allowed in the examination
room.
5. Write your examinations numbers on every page of your answer sheet(s).

SECTION A (15 Marks

Answer all questions in this section.

1. For each of the items (i)-(x) choose the correct answer among the given alternative ]s and
write its letter beside the item number in the answer booklet provided.

(i) Viruses are considered to be non-living because:

A They are only active in the contents of a living cell B They have true nuclei
C The body is covered by cell wall
D They are single cell Eukaryotic Organism
E They have cell wall made up of cellulose.

(ii) Select the items that indicates the best Match in the vitamin –
deficiency A Vitamin A ………dry scalyskin
B Vitamin B .............. loss of appetite and yawning
C Vitamin C.............. anaemia and high blood pressure
D Vitamin D ............. soft deformed bones
E Vitamin E ..............poor night vision

(iii) Which of the following is a chemical substance that catches fire easily?
A. Corrosive B. Flammable C. Oxidant
D. Irritant E. Harmful

(iv) When students were conducting private study at right, lights went off suddenly.
Which of the following changes occurred in the eyes of the students?
A. The lens become thicker B. The pupils become
large
C. The ciliary muscle relaxed D. The lids closed
E. The eyes opened wider
 (v) One of the following is the principle of good manner
A Eating fast B Speaking respectively C Throwing food
D Wearing tight clothes E Washing the body everyday
(vi) Which of the following is formed immediately after fertilization?
A A placenta B An embryo C A foetus
D Amniotic fluid E A zygote
(vii)
A type of germination where by the Cotyledons is raised above the ground is called
A Epigeal B Hypogeal C Hypocotyls
D Tap root E Epicotyls
(viii) The offspring produced by mating the F1generation is known as
A F3generation B F1products C
F2products D New generation E
Genetic generation
(ix) Which food substance can be tested by using Iodinesolution?
A . Protein B. Starch C . Carbohydrate
D . Non reducing sugar E . Reducing sugar
(x) People with blood group ............. are called universal recipients
A. AB B .B C .O
D. A E .None of the above
2. Match the phrases in List A with the corresponding responses in List B, by writing the letter
of the correct alternative in List B on the answer sheet provided.

LIST A LIST B
(i) Bi concave in shape, lack a nucleus A. Leucocytes
(ii) Have irregular shape which respond to infections B. Erythrocytes
(iii) Fragments of cells produced in the bone marrow C. Thrombocytes
(iv) A fluid tissue consisting of white cells, red cells, platelets and D. Thrombin
plasma. E. Phagocytes
(v) The fluid part of the blood. F. Plasma
G. Capillaries
H. Blood

SECTION B (60 Marks)

Answer all questions in this section.

3. (a) Define the following terms as used in biology.

(i) Biology laboratory (ii) Botany
(b) Give the function of the following parts of light microscope (One function in each).
(i) mirror (ii) objective lens (iii) Eye piece
(iv) Base (v) Limb or Arm ( vi) Clip
( vii) Course adjustment (viii) Stage

4. (a) (i) What are the raw materials for photosynthesis

(ii) List one product of photosynthesis

(b)State how the ileum is adapted for absorption function.

5. (a) Differentiate between a zygote and a sperm

(b) Name the hormone in human body which
 (i) Secreted during birth to initiate labour (ii) Stimulate milk production
(iii) Re absorption of water in the kidney (iv) Sodium absorption in the kidney.

6. (a) Differentiate between epigeal and hypogeal germination

(b) Mention condition necessary for seed germination
(c) Describe changes occurs during seed germination

7. (a) What do you know by the following terms

(i) Genetics ii). Albinism iii). Complete dominance iv). Mutation
(b) Mr and Mrs Msakanjia happen to have four children in their marriage, one of them
is albino, use the genetic diagram to prove the statement above.
8. (a) Give the
function of
(i) Red blood cell
(ii) White blood cells
(b) Outline six roles played by the blood in Human beings.

9. (a) Explain the term Osmoregulation

(b) Briefly explain the mechanisms of regulating sugar level in theblood.

10. (a) How could the body remove or destroy a bacterium that lands
(i) On the cornea (ii) On the Hand (iii) In the bronchus (iv) In the stomach
(b) Explain why it is
(i) Not health to sleep in a closed room with many potted plants
(ii) Dangerous to sleep in a poorly ventilated room with a charcoal burner on.
11. (a) Write short notes on the following terms; food chain and food web.
(b) Construct sensible food web from the given organisms, Grass, Grass hopper,
Rabbit, Toad, Snake, and Vulture

12. (a) Differentiate between Sexual reproduction and Asexual reproduction

(b) State two behaviors which may lead to the following risk.
i) STD’s ii). HIV infection

SECTION C (25 Marks)

Answer two (2) questions from this section. Question 13 is compulsory.

13. During the rainy season the common problem of eruption of diseases become more serious.
Cholera has been a long-term problem in Tanzania. The government tried to eradicate the disease
but has not been very successful
(a) Explain the possible reasons that have led to the failure of problem of cholera
(b) Explain how this disease can be eradicated successfully in terms of its mode of
Transmissions, control, and curative methods.

14. Food preservation is very important in Human life. Discuss its importance under the following
guideline
(a) Need for preservation
(b) Local (traditional) food preservation methods and their biological effects
(c) Advantages of local food preserving methods.

15. With the aid of well labeled diagram explain clearly how the gaseous exchange occurs across
alveolus.
*************************************************************************
 THE UNITED REPUBLIC OF TANZANIA
PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT
FORM FOUR EXAMINATION - SERIES 07
BIOLOGY
TIME: 3:00 Hours Year : 2022

INSTRUCTIONS

1. This paper consists of sections A, B and C with a total of fifteen (15) questions

2. Answer all questions from section A and B and only two (2) questions in section C,
whereby question number thirteen (13) is compulsory.

3. All writings should be in blue or black ink pen except the diagram that must be drawn
in pencil.

4. Calculators, cellular phones and any unauthorized materials are not allowed in the
examination room.

5. Write your Examination Number in every page of your answer sheet(s)

SECTION A (15 MARKS)

1. For each of the following items (i-x) write the correct answer among the given
alternatives and write its letter beside the item number in the answer sheet(s)
provided.

i. Animals show irritability this means that they?

A. Always move
B. Are capable of growing
C. Reproduce
D. Respond to stimuli
E. Are able to loco mote

ii. Are conditions or factors that can change or be changed in an experiment.

A. Hypothesis
B. Problems
C. Variable
D. Conclusion
E. Experiment

iii. If your asked to prepare a first aid kit with its components, which of the following
you will not include?
A. Iodine tincture
B. Sterilized cotton wool
C. Medicine to cure diseases
D. Pair of scissors
E. Soap
 iv. Example of diseases caused by bacteria are
A. Tuberculosis, Cholera and Ebola
B. Tuberculosis, Typhoid and Cholera
C. Elephantiasis, AIDs and sleeping sickness
D. Malaria, Bilharzias and cancer
E. Measles, Amoebic dysentery and chicken pox

v. If you go to a market and buy sweet potatoes and onion you will actually be buying
A. Onion bulb and stem tuber
B. Root tubers and fleshy leaves
C. Root tubers and stem tubers
D. Stem tuber and fleshy leaves
E. Stem tuber and Onion bulb

vi. Oxygen passing from the atmosphere into the blood of an organism takes one of
the following routes
A. Bronchi ____ Bronchioles ____ Trachea ____Alveoli
B. Trachea ____ Bronchioles ____ Bronchi ____ Alveoli
C. Bronchioles ____ Bronchi____ Trachea ____ Alveoli
D. Trachea ____ Bronchi ____ Bronchioles ____ Alveoli
E. Alveoli ____ Trachea ____ Bronchi ____ Bronchioles

vii. If the human blood is mixed with distilled water and examined under microscope,
the red cell would have?
A. Shrunken a little
B. Swollen slightly
C. Stayed in some size
D. Totally shrink
E. Swollen and burst

viii. Compared with the pollen grain of a wind pollinated flowers and that of an insect
pollinated flower will be
A. Rough, dry and produced in large amount
B. Smooth sticky and produced in small amount
C. Rough, dry and produced in small amount
D. Rough sticky and produced in small amount
E. Smooth, dry and produced in large amount

ix. Fern plants are vascular plants like mango tree and coconut plant, but ferns differ
by?
A. Processing only one seed leaf
B. Reproducing by spores
C. Having seed in seed box
D. Lacking xylem and vessels
E. Having by-pinnate leaves

x. During menstrual cycle, as the level of estrogen start to rise

A. LH-Luteinizing hormone start to rise
B. Progesterone hormone in inhibited
C. Follicle stimulating hormone (FSH) is inhibited
D. Corpus Luteum begins to form ovum
E. Testosterone production is stimulated
2. Match the phrases in list A and responses in list B by writing the letter of the
correct response from list B beside the item of list A in your answer sheet(s)

LIST A LIST B

i. Reduce reflection of light within A. Retina

the eyes B. Choroids
ii. Control the intensity of light C. Lens
entering the eye D. Iris
iii. Cells sensitive to light of low E. Cones
intensity F. Rods
iv. Control the shape of the lens G. Blind sport
v. Cause reflection of light in the H. Ciliary body
eye I. Aqueous humor
J. Cornea

SECTION B (60 MARKS)

Answer all questions in this section

3. a) What do you understand by the following terms as used in biology

i. First aid kit
ii. Risks
iii. An Accident
iv. Poisoning

b) Halima’s son was stung by honey bee but she is not familiar on how to help her
son. As a biologist assist her by outlining four procedures of giving first aid to her
son.

4. a) State the conditions necessary for seed germination and briefly describe
how they facilitate germination

b) With vivid examples differentiate epigeal germination from hypogeal germination

5. a) Outline any two (2) distinctive characteristics of phylum arthropoda

b) (i) Mention the classes of phylum arthropoda
(ii) Name one (1) representative member for each class you have
mentioned in 5 (b) (i) above

6. a) Suggest how
i. Life style and diet may cause problem with circulatory systems
ii. Why does the heart beat fast during exercise?
b) Explain why some trees are killed when a ring bark is removed in their
stems

7. a) How are lung alveoli suited for their function?

b) List four factors that affect the rate of respiration
c) What are the product of anaerobic respiration in?
i. Plants
ii. Animal

8. a) what meant by the following term

i. Natural environment ii). Ecosystem
 b) (i). List members or components of an ecosystem and give function of each
(ii). Construct the food web using the following organisms;
Worm, insects, field mice, toad, green plants, snake and hawk

9. The diagram in figure 1 below is reflex arc in human being, study the diagram and
answer the questions that follow

Figure1

a) Name labeled parts A-F

b) (i) Outline the function of parts B, C and D
(ii) If someone touches hot object, what is the response shown by part E and
F

10. The middle aged man in regularly visiting local traditional healer, suspecting that he
has been be witched. He has prolonged cough and emitting blood-stained sputum
whenever he coughs. He cannot eat properly he has poor appetite and suffers weight
loss. He has surprised that he sweat a lot during the night
a) What would your advice the man to do?
b) Which disease is he likely to be suffering from
c) List down the causes of the disease
d) How it transmitted?
e) Mention the preventive measures

11. a) Define the term excretion

b) Why do plant lack special excretory organs?

12. a) What growth curvature mean as applied in movement?

b) Name four (4) types of joint found in the human skeleton and for each describe
and give an example.
 SECTION C (25 MARKS)
Answer only two (2) questions but question number thirteen (13) is compulsory.
13. Write an essay on Corona Virus Disease (COVID-19) using the following guidelines /
outlines
• Causative agent
• Transmission of the disease
• Symptoms of the disease
• Preventive measure against the disease
• Treatment

14. Mr. Pondamali believed that living things do not change with course of time. As
biologist convince him by explaining the evidences of organic evolution. Give four
points.

15. a) What is genetics?

b) In cross between red cow and white bull, ¼ of the F2 generation were red cow, ½
were roan and ¼ were white bull
i. What is the type of inheritance?
ii. Show how this phenotype were obtained

******************************************************************
 THE UNITED REPUBLIC OF TANZANIA
PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT
FORM FOUR EXAMINATION - SERIES 08
BIOLOGY
TIME: 3:00 Hours YEAR: 2022

INSTRUCTIONS

1. This paper consists of sections A, B and C with a total of fifteen (15) questions.
2. Answer all questions in section A and B, and two(2) questions in section C where by question number eleven
(11) is compulsory
3. All writings should be in blue or black ink pen EXCEPT for diagrams that must be drawn in pencil
4. Calculators, cellular phones and any authorized materials are not allowed in the examination room.
5. Write your Examination number on every pages of your answer booklet

SECTION A (15 Marks)

Answer all questions in this section
1. For each of the items (i-x) choose the correct answer among the given alternatives and write its letter
besides the item number in the answer booklet provided.
i.One of the following is not part of the reproductive system of a female mammal
A. Vagina B. Urethra C.Fallopian tube D. Uterus E. Ovary
ii) A phylum consisting of species with jointed appendages and exoskeleton is known as
A. Chordate B. Annelida C. Arthropoda D. Platyhelminthesis E. Nematoda
iii) Tongue rollers in genetics is an example of
A. Mechanical digestion
B. Lubricating food
C. Continuous variation
D. Discontinuous variation
E. Swallowing
iv) Tympanic membrane is another name for ………….
A. Ossicles
B. Eardrum
C. Eustachian tubes
D. Cochlea
E. Pinna
v) Example of diseases caused by bacteria are
A. Tuberculosis, Cholera and Ebola
B. Malaria, Bilharzias and Cancer
C. Elephantiasis, AIDS and Sleeping sickness
D. Measles, Amoebic dysentery and Chickenpox
E. Tuberculosis, Typhoid and Cholera
vi) Oxygen passing from the atmosphere into the blood of an animal takes one of the following routes:
A. Bronchi – bronchioles – trachea – alveoli
B. Trachea – bronchioles – bronchi – alveoli
C. Trachea – bronchi – bronchioles – alveoli
D. Bronchioles – bronchi – trachea - alveoli
E. Alveoli – trachea – bronchi – bronchioles
vii) The function of hydrochloric acid in food testing experiment is
A. To decolourise food sample
B. To test reducing sugar
C. To oxidize the food sample
D. To neutralize sugary food
E. To hydrolyse complex sugar to simple sugar

viii) The transport of food substances against the concentration gradient in a cell by using energy is
called
A. Active transport E. Diffusion
B. Osmosis
C. Passive transport
D. Mass transport
ix) In mammals, the organ which acts as a reservoir for carbohydrate is
A. Pancreas
B. Liver
C. Spleen
D. Stomach
E. Rectum
x) If you go to a market and buy some potatoes and onion you will actually be buying
A. Onion bulb
B. Root tubers and fleshy leaves
C. Root tubers and stem tubers
D. Stem tubers and fleshy leave
2. Match the phrases in List A with the responses in List B by writing the letter of the correct
response from List B beside the item number of List A in your answer booklet.
LIST A LIST B
i. Controls the pituitary gland A. Synapse
ii. Concerning with reasoning, intelligence B. Effector
and judgement. C. Hypothalamus
iii. The nervous pathway taken by impulse D. Reflex arc
in reflex action E. Medulla oblongata
iv. Controls and coordinate body balancing F. Cerebrum
organs, thus making accurate movement G. Cerebellum
possible H. Peripheral nervous system
v. A gap through which impulses pass
when travelling from one neuron to
another

SECTION B (60Marks)
Answer all questions in this section

3 a) (i) What is a tissue?

(ii) Name two animal and plant tissues
b) Define the term cell differentiation
c) Briefly explain the importance of cell differentiation
4. a) Explain the concept of mitosis
b) Mention stage of mitosis
c) Explain the significance of mitosis in growth
5. a) Why biology? Give two reasons
b) Classify the following organisms to class level giving one distinctive features for each
classification level
a) Bean plant b) Toad
6.a)What do you understand by the term Binomial nomenclature?
b) Give two (2) advantages of scientific naming of living organism
c) Why is it difficult to destroy viruses?
7 a) i)What is shock?
ii) What are the causes of shock?
b) Give four importance of first aid

8. a) i) Briefly explain why pituitary gland is called master gland?

ii) Explain why during cold we lose sense of smell
b) Insulin and glucagon work antagonistically, Explain.

9. a) Explain the adaptation of the lungs for gaseous exchange

b) What is the biological importance of shivering during cold weather?
c) Explain why some trees are killed when a ring of bark is removed their stems

10. a) What is the composition of mammalian blood ?

b) Explain clearly the functions of mammalian blood.

11. Explain why

i) It is possible for a person to swallow something while standing on his head
ii) One does not urinate frequently on a hot day?
12. Study the structure of a hip joint in the mammalian skeleton

i) Name the parts of labelled A, B, C, D, E and F

ii) State the functions of parts B and C
iii) Name the type of joint represented by structure above and state one characteristic of such a
joint
 SECTION C (25 Marks)
Answer only two (2) questions but question number eleven (11) is compursaly
13.a)A black rabbit homozygous for coat colour was crossed with a white rabbit of unknown
genotype. The offspring was all black. By means of a diagram and symbols find the
genotype of the parent and offspring.
b) i) What is sex- linked character?
ii) If coat colour in rabbit question number 8 (a) is a sex- linked character, what would be the
phenotypes and genotypes of offspring produced from a cross between a black male and a
white female?
14.Among the minerals most essential to our bodies are Iron, calcium and sodium. Discuss these
minerals under the following headings
i) Roles to the body
ii) Natural common sources
iii)Deficiency disorders caused by each to man

15.Write an essay on Bilharzias using the following outline

i) Causative agent
ii) Transmission of the disease
iii) Symptoms of the disease
iv) Preventive measures against the disease

*************************************************************************
 THE UNITED REPUBLIC OF TANZANIA
PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT
FORM FOUR EXAMINATION - SERIES 09
BIOLOGY
TIME: 3:00 Hours YEAR: 2022

INSTRUCTIONS

1. This paper consists of sections A, B and C with a total of fifteen (15) questions.
2. Answer all questions in sections A and B and TWO questions from section C in
which question 13 is compulsory
3. All writing should be in blue or black pen, except for diagrams which must be in pencil
4. Cellular phones and any unauthorized materials are not allowed in the examination room.
5. Write your examinations numbers on every page of your answer sheet(s).

SECTION A (15 Marks)

Answer all questions in this section

1. For each of the items (i) -(x), choose the correct answer among the given alternatives and
write its letter beside the item number in the answer booklet provided
(i) Which of the following is the most important difference between plants and animals?
A Growth B Movement C Nutrition
D Sensitivity E Development
(ii) The following are the branches of biology. Identify one which is not
A Microbiology B Ecology C Genetics
D Science E Mycology
(iii) Which of the following specialized cells in plant is responsible for the high
concentration of chloroplast responsible for photosynthesis?
A Chlorophyll B Palisade C Guard cell
D Root hair cells E Xylems
(iv) The following are examples of water borne diseases:
A Malaria and Bilharzias B Diarrhea and malaria
C Yellow fever and Typhoid D Cholera and Typhoid
E Malaria and Typhoid
 (v) Mutual interaction between two species is described by which of the following
statement?
A Both lives as parasite B Both benefit and flourish
C One harmed and the other benefit D Both neither benefit nor harmed
E Non –of the above is correct
(vi) A very young tadpole breath by means of
A Spiracle B Gills C Segments
D Nostril E Skin
(vii) Salome gets an accident and found that she could hardly maintain her body
equilibrium. Which one among the following structures of her body was probably
damaged?
A Cochlea B Medullar Oblongata C Semi secular canal
D pituitary canal E Auditorium canal
(viii) Pancreases secrete pancreatic juice which contain the following enzymes
A Bile, Lipase and Trypsin B Trypsin, Bile and Amylase
C Amylase, Trypsin and mucus D Renin, Trypsin and amylase
E Trypsin, mucin and lipase
(ix) -------- is the force responsible for pulling of water to the top of the tall trees
A Capillarity pull B Transpiration pull C Osmotic
pressure
D Turgor pressure E Mass flow rate
(x) -------- and --------- grows into shoot and root respectively during seed germination
A Plumule and Epicotyl B Plumule and radicle
C Radicle and Plumule D Seed and Hilum
E Epicotyl and plumule
2. Match the responses in List A with responses in List B by writing the letters of the
correct response beside the item number in the answer booklet provided.
LIST A LIST B
(i) Maintenance of constant internal A. Diabetes mellitus
environment B. Nephron
(ii) Deamination of Amino Acid C. Kidney
(iii) Blood capillaries within Bowman’s D. Glomerulus
capsule E. Liver
(iv) Sugar in urine F. Diabetes inspindus
(v) Functional unit of a kidney G. Regulation
H. Homeostasis
I. Urination
J. Excretion
 SECTION B (60 Marks)
Answer all questions in this section
3 (a) Name the locomotory organs of the following organisms
(i) Amoeba (ii) Euglena (iii) Man (iv) Earthworm
(b) Differentiate between movements and locomotion.
4 (a) (i) What are the raw materials for photosynthesis
(ii) List one product of photosynthesis
(b) State how the ileum is adapted for absorption function.
5 (a) Give four forms and shapes of bacteria
(b) Outline four economic importance of useful bacteria.
6. (a) Briefly explain the meaning of the following biological terms

(i) Seed germination (ii) Epigeal germination

(iii) Meristerms (iv) Primary growth in plants

(b) State four significances of water during seed germination.

7. (a) How could the body remove or destroy a bacterium that lands

(i) on the cornea (ii) on the Hand (iii) on the bronchus (iv) in the
stomach

(b) Explain why it is

(i) Not health to sleep in a closed room with many potted plants

(ii) Dangerous to sleep in a poorly ventilated room with a charcoal burner on.

8. (a) Write short explanation of the following terms

(i) Excretion (ii) Neurone
(b ) Animal brain has different part with different functions, discuss the function of the
following parts
(i) Motor neurons (ii) Relay neurons
(iii) Sensory neurons (iv) Medulla oblongata
9. (a) Explain the meaning of the following terms in relation to coordination
(i) Reflex action
(ii) Reflex arc
(b) Distinguish between simple and Conditioned reflect action. Give four points.
10 (a) (i) Define Immunity
(ii) Distinguish between natural active immunity and artificially active immunity
(b)Name four diseases which children are immunized
11. (a) Explain the meaning of the following terms:

(i) Excretion (ii) Deamination (iii) Detoxification (iv) Secretion

(b) The following are the main excretory products in man carbon dioxide, excess water
and Urea

(i) Name the major organs through which each is excreted

(ii) Name two substances that the body would be deficient following heavy sweating
12. (a) Elaborate any three traditional and three modern methods of food processing and
preservation.

(b) Show clearly the importance of Breast- feeding in children (Give 3 points)

SECTION C

Answer all questions from this section, question 13 is compulsory

13. (a) Briefly discuss the following theories of origin of life.

( i ) Special creation
( ii ) Chemical evolution theory

(b) Outline Lamack’s Theory of evolution and explain with specific examples why
biologists dispute the theory today.

(c) Outline the main differences between Lamack’s and Darwin’s theories of evolution.

14. (a) What are the four major differences between Deoxyribonucleic acid (DNA)
Ribonucleic Acid (RNA).

(b) A pure breeding pea plant with smooth seeds was crossed with pure breeding pea
plant with wrinkled seeds

(i) Show the result of F1 and F2 on selfing F1 .

(ii) Work out the phenotypic and genotypic ratio of F2.
15. Write an essay on the transportation in plants using the following guidelines
(a)Meaning of transportation
(b)The importance of transportation
(c )The adaptation of features which enable the plant to reduce water loss.

*********************************************************************
 THE UNITED REPUBLIC OF TANZANIA
PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT
FORM FOUR EXAMINATION - SERIES 10
BIOLOGY
TIME: 3:00 Hours YEAR: 2022

INSTRUCTIONS

1. This paper consists of sections A, B and C with a total of 15 questions.

2. Answer all questions in sections A and B and two (2) questions from section C of which
question 13 is compulsory.
3. Section A carries fifteen (15) marks, section B sixty (60) marks and section C carries twenty
five (25) marks.
4. All writings should be in blue or black ink, except for diagrams that must be drawn in pencil.
5. Cellular phones and any unauthorized materials are not allowed in the Examination room.
6. Write your Examination Number on every page of your answer booklet(s)

SECTION A: (15 Marks)

Answer all questions in this section
1. For each of the following items (i) – (x), choose the most correct answer from among the given
alternatives and write its letter beside the item number in the answer booklet(s) provided:

(i) When the first day of menstruation was 8th April on which date is a woman of 28 days
cycle most likely to ovulate?
A. 26th March
B. 22nd April
C. 5th May
D. 16th April E. 21st April.

(ii) Its cell body is located within the central nervous system:
A. Sensory neurone
B. Spiral neurone
C. Motor neurone
D. Inter neurone
E. Cranial neurone.

(iii)Tonoplast is the membrane found in:

A. Nucleus
B. Chloroplast
C. Mitochondrion
D. Vacuole
E. Cell membrane.
(iv) Which of the following organism may have the same nutritional value with plants:
A. Amoeba
B. Euglena
C. Paramecium
D. Yeast E. Plasmodium.

(v) The plant which bears one of the reproductive structures only (Stamen/Pistil) is referred
to as:
A. Complete flower
B. Incomplete flower
C. Monoecious D. Dioecious
E. Hibiscus.

(vi) A process of formation of chiasmata occur in:

A. Prophase I of meiosis I
B. Prophase I of meiosis II
C. Prophase of mitosis D. Metaphase I of meiosis I
E. Metaphase of mitosis.

(vii) The type of immunity that can prevent a young individual against measles is
called:
A. Active artificial immunity
B. Artificial passive immunity
C. Active natural immunity D. Natural passive immunity
E. Natural immunity.

(viii) A concave notch of kidney where renal artery, renal vein, ureter, nerve
lymphatic vessel converge is called:
A. Renal pelvis
B. Hilum
C. Hilium
D. Hillum E. Hillium.

(ix) Why was Lamarck’s theory of “use and disuse” criticized? A. People didn’t like his
ideas
B. Phenotypically acquired characteristics are not
inheritable
C. Went against many religious beliefs D. He was not the
father of evolution
E. He was not real scientist.

(x) Which of the following sets include characteristic that is not for living things?
A. Feeding, irritability and growth
B. Reproduction, death and definite shape
C. Excretion, locomotion and feeding
D. Growth, movement and respiration
E. Movement and gaseous exchange.
2. Match the response in list B with the phrases in list A by writing the letter of the correct response
from list B beside the item number of list A in your answer booklet provided:

LIST A LIST B

(i) A structure the nucleus that contains DNA A. F1 : 3:1

(ii) Offspring from genetically unlike parents B. F1 : 1:2:1
(iii) Specific site of a gene C. Dominant gene
(iv) Parental genotype Tt x Tt D. DNA
(v) A gene that conceals the expression of another gene E. Locus
F. Hybrid
G. Heterozygote
H. Gene

SECTION B: (60 Marks)

Answer all question in this section

3. (a) How do the following blood components contribute to our life processes?
(One point for each)

(i) Thrombocytes
(ii) Plasma
(iii)Leukocytes

(b) State three (3) structural differences between a red blood cell and white blood cell.

4. (a) Define the following terms as used in growth:

(i) Germination
(ii) Seed dormancy
(iii)Seed viability

(b) A maize garden was observed to have plants of different height and size despite being of
the same age and receiving/equal treatment. Give reasons for such observation. (Any three
(3) points)

5. (a) What is digestion?

(b) Explain the following biological observations:
(i) Unpolished cereals are more important in women than men.
(ii) “Pancreas is the site for secretion only but not digestion”. Justify.

6. (a) Differentiate between excretion and regulation.

(b) State parts of the body where the following excretory products are formed
(i) Bile ii). Sweat

(c) Excessive intake of sugary food stuffs may not affect the healthy body. Explain
7. Highlight two differences for each of the following:
(a) Ball and socket and hinge joints
(b) Skeletal muscle and cardiac muscle

8. The rate of respiration varies from one person to another. Give three (3) reasons.

9. (a) Write down the genotypes of the following individuals:

(i) Haemophilic male
(ii) Haemophilic female
(iii) Normal male
(iv) Normal female
(v) Normal but carrier female
(b) What will be the percentage of haemophilic girls in F1 when haemophilic male marries a
carrier female for the trait.

10. Clearly explain what will happen if the following parts as the brain will be severely damaged.
(a) Medulla oblongata
(b) Hypo thalamus
(c) Cerebellum

11. (a) Define the term cell differentiation as used in Biology.

(b) Use at least two (2) examples to prove that plant cells are specific in their functions.
.

12. All living things share common characteristics. Briefly explain by using three (3) points.

SECTION C: (25 Marks)

Answer two (2) questions in this section. Question 13 is Compulsory.

13. Life on Earth would have been impossible without the presence of bacteria. Justify.

14. Write an essay on communicable diseases and how they are transmitted from one person to
another (give one (1) example for each mode).

15. In our society, many people believe that it is only couples who are planning to get married
should seek VCT services. Use your Biology knowledge to impart them with proper
understanding on “who should seek VCT services”. (5 points).
 THE UNITED REPUBLIC OF TANZANIA
PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT
FORM FOUR EXAMINATION - SERIES 11
BIOLOGY
TIME: 3:00 Hours YEAR: 2022

INSTRUCTIONS

1. This paper consists of sections A, B and C.

2. Answer ALL questions in section A and B and only two questions from section C. (question
14 is compulsory).
3. Except for diagrams that must be drawn in pencil, all writings should be in blue or black ink.
4. Write your examination Number on every page of your answer booklet.

SECTION A (15 MARKS)

Answer all questions in this section

1. For each of the items (i – x), choose the correct form among the given alternatives and write
its letter besides the item number in the answer booklet (10 MARKS).
i. The central nervous system consists of:

A. The brain and the spinal cord

B. The spinal nerves
C. The spinal cord and spinal nerves
D. The sympathetic and parasympathetic nerves
E. The brain and spinal nerves
ii. Hormone are carried from one part of the body to another:
A. Along ducts
B. Along nerves
C. By the blood
D. Down the hollow part of the spinal cord
E. By the water
iii. During cold weather shivering occurs in a mammalian body in order to;
A. Shake off coldness
B. Produce sweet
C. Relax the muscles
D. Generate heat
E. Prevent heat
iv. Shortly after an egg is fertilized the product is known as:
A. Embryo
B. Zygote
C. Foetus
D. Young baby
E. Children
v. Which one of the following is correct order of events?

A. 𝑓𝑒𝑟𝑡𝑖𝑙𝑖𝑧𝑎𝑡𝑖𝑜𝑛 → 𝑖𝑚𝑝𝑙𝑎𝑛𝑡𝑎𝑡𝑖𝑜𝑛 → 𝑜𝑣𝑢𝑙𝑎𝑡𝑖𝑜𝑛

B. 𝑜𝑣𝑢𝑙𝑎𝑡𝑖𝑜𝑛 → 𝑓𝑒𝑟𝑡𝑖𝑙𝑖𝑧𝑎𝑡𝑖𝑜𝑛 → 𝑖𝑚𝑝𝑙𝑎𝑛𝑡𝑎𝑡𝑖𝑜𝑛
C. 𝑖𝑚𝑝𝑙𝑎𝑛𝑡𝑎𝑡𝑖𝑜𝑛 → 𝑜𝑣𝑢𝑙𝑎𝑡𝑖𝑜𝑛 → 𝑓𝑒𝑟𝑡𝑖𝑙𝑖𝑧𝑎𝑡𝑖𝑜𝑛
D. 𝑜𝑣𝑢𝑙𝑎𝑡𝑖𝑜𝑛 → 𝑖𝑚𝑝𝑙𝑎𝑛𝑡𝑎𝑡𝑖𝑜𝑛 → 𝑓𝑒𝑟𝑡𝑖𝑙𝑖𝑧𝑎𝑡𝑖𝑜𝑛
E. 𝑓𝑒𝑟𝑡𝑖𝑙𝑖𝑧𝑎𝑡𝑖𝑜𝑛 → 𝑜𝑣𝑢𝑙𝑎𝑡𝑖𝑜𝑛 → 𝑖𝑚𝑝𝑙𝑎𝑛𝑡𝑎𝑡𝑖𝑜𝑛
vi. The dry mass is more preferred to fresh weight in estimating growth in plants. This is because it is
more accurate due to fact that:
A. Dead organisms are easier to work with
B. Dry plants are lighter to measure
C. It measure even irregular organism
D. It exempts the variations due to water content
E. It is simple that other methods
vii. If boiled with Fehling’s solution (Benedict’s solution) which is blue, the mixture first turn green
and finally produces an orange, yellow or red coloured precipitate. This is the test for: A. Lipids
B. Protein
C. Sucrose
D. Starch
E. Reducing sugar
viii. Peristalsis can be defined as the :
A. Wave like movements caused by muscular contraction and relaxation along the
digestive tract that help to propel food.
B. Closing of the stomach entrance by a sphincter muscle.
C. Closing off trachea by the epiglottis in swallowing.
D. Surrounding of food particles by the pseudopodia of amoeba
E. Opening of trachea by the epiglottis in swallowing.

ix. Consider this food chain; 𝐺𝑟𝑎𝑠𝑠 → 𝐺𝑟𝑎𝑠𝑠ℎ𝑜𝑝𝑒𝑟𝑠 → 𝐵𝑖𝑟𝑑𝑠; the birds in this food chain are:
A. Producers C. Primary consumers D. Secondary consumer
B. Tertiary consumers E. Decomposer
 x. In mammals, deoxygenated blood from the body enters the heart through:

A. Left vertical
B. Right vertical
C. Right atrium (auricle)
D. Left atrium (auricle)
E. Pulmonary vein.
2. Match the phrases in list A with the responses in list B by writing the letter of the correct
response from list B beside the item number of list A in your answer booklet (5 marks).
LIST A LIST B

i. Reproduction, growth, respiration and A. Movement is possible to only one direction

movement B. Movement is possible to all direction
ii. Temperature, wind, light, soil, Water, C. Abiotic factors
atmospheric pressure and altitude D. Characteristics of living things
iii. Hinge joint E. Biotic factors
iv. Pressure of the cell contents against the cell F. Hydrolysis
wall. G. Characteristics of non living things
v. A chemical breaking down of a substance
H. Turgor pressure
involving addition of water.
I. Wall pressure
J. Photolysis

SECTION B (60 MARKS)

Answer ALL questions in this section.
3. (a) What do you understand by the following terms (i) Biology (ii) Zoology (b) Why it is
important to study Biology? Give four reasons.
4. (a) Briefly explain the following terms. (i) Trophic level (ii) Food chain (iii) Food web (b)
With examples, briefly explain how the following interactions of living organism take place.
(i) Predation (ii) Parasitism (iii) Mutualism.

5. (a) What are the characteristics of an insect-pollinated flower?

(b) Define the term cross-pollination
(c) Mention three agents of pollination
6. (a) Give the long meaning of the following abbreviation terms (i) HIV (ii) STIs (iii) STDs
(b) List the organs responsible for gaseous exchange in the following organisms. (i) Goat
(ii) Grasshopper (iii) Frog
7. (a) Explain any two theories of organic of evolution.
(b) Name the structures used for movement in the following: (i) Amoeba (ii) Paramecium (iii)
Fish (iv) Mammals (v) Earth worm.
8. (a) What is shock?
(b) What are the causes of shock? (any two causes) (c) List down any three causes of
fainting?
9. (a) Briefly describe how water, air and temperature facilitate seed germination.
(b) Differentiate epigeal germination from hypogeal germination (three differences).
10. (a) State three basic principles of waste disposal (b) Explain three effects of poor waste
disposal.
11. (a) Define the terms “Classification system” and “Taxonomy”
(b)(i) List the types of classification system
(ii) Give two differences between the classification systems you have listed in (b)(i)

12. In an experiment, a variety of garden peas having a smooth seed coat was crossed with a
variety having a wrinkled seed coat. All the seeds obtained in the F1 had a smooth seed coat.
The F1 generation was selfed.
The total number of F2 was 7324. Let the gene for smooth seed coat be S.

(a) Work out the genotypes for the F1.

(b) Work out the genotype and phenotype ratio of F2.
(c) Calculate the number of the; (i) Wrinkled seeds in F2 (ii) Smooth seeds in F2

SECTION C (25 MARKS)

Answer only two questions in this section; question 14 is compulsory
13. (a) A group of form IV students from Chita Secondary School had a study visit to St. Francis
Hospital at Ifakara. They noted a patient with Sunken eyes, Severe dehydration, weak pulse,
deep breathing, vomiting and Convulsions.
(i) What could be the possible disease that the patient was suffering from?
(ii) Briefly explain the causes and controls / preventive measures of the disease
mentioned in (a)(i) above.
14. Most of the young people today practice risky behaviours thinking that it is a modern style of
life. This is a wrong concept. Discuss the factors which contribute to risky behaviours among
young people in the society and their consequences.
15. Rape is among of the current social problems in our community. Write an essay on rape,
based on the following: - Meaning of rape.
- Possible causes of rape.
- Consequences of rape.
- Ways of avoiding rape.
-
************************************************************************
 THE UNITED REPUBLIC OF TANZANIA
PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT
FORM FOUR EXAMINATION - SERIES 12
BIOLOGY
TIME: 3:00 Hours YEAR: 2022

INSTRUCTIONS

1. This paper consists of sections A, B and C with a total of 15 questions.

2. Answer all questions in sections A and B and two (2) questions from section C of which
question 13 is compulsory.
3. Section A carries fifteen (15) marks, section B sixty (60) marks and section C carries twenty
five (25) marks.
4. All writings should be in blue or black ink, except for diagrams that must be drawn in pencil.
5. Cellular phones and any unauthorized materials are not allowed in the Examination room.
6. Write your Examination Number on every page of your answer booklet(s)
**************************************************
THE END
 FORM FOUR EXAMINATION - SERIES 01
MARKING SCHEME
1.
i ii iii Iv v vi vii viii ix x
C A A B D C B A D C
( 1 MARK @ =10).

2.
i ii Iii iv v
D A E F C
(1MARK @ = 5)
3. i. Contains pathogens
ii. Emits harmful radiations
iii. They are poisonous, can cause death
iv. Can burn the skin or corrode some parts (1 MARK @ = 6)
v. can catch fire easily
vi. Can make small fire large

4. (a) Group A – insect pollinated flowers

Group B – wind pollinated flowers (@ 1 MARK = 2)
(b)
Flowers in group A Flowers in group B
i. they have brightly colored petals -they have dull colored petals
ii. they produce nectar -they do not produce nectar
iii. produce scent -do not produce scent
iv. Produce few pollen grains -produce many pollen grains
(@ 1 MARK = 4)
5. –in high sugar level, the islets of Langerhans of the pancreas secrete insulin hormone which
converts the excess sugar (glucose) in to glycogen. This will reduce the amount of sugar in the
blood. (3 MARKS)
- In low blood sugar level, glucagon hormone will be secreted. This converts the stored glycogen
to glucose, hence increasing sugar level in the blood to meet the body needs. (3 MARKS)
6. (a) mitosis is a cell division that results to two diploid cells. (2 MARKS)
(b) i. brings about growth
ii. Brings about cell replacement
iii. Brings about asexual reproduction (@ 1 MARK = 4)
iv. Brings about regeneration

7. i. they are thin to facilitate diffusion over short distance

ii. They are moist to dissolve gases before diffusion
iii. They are well supplied with blood vessels for transporting gases (@ 1.5 MARKS = 6)
iv. They are large for maximum gaseous exchange

8. (a) Maize – class monocotyledoneae

Beans – class dicotyledoneae (1 MARK @ = 2)
(b) i. they are used as food
ii. They balance atmospheric gases
iii. They provide habitat to some organisms (@ 1 MARK = 4)
iv. They are source of income

9. i. used for grinding/crushing substances

ii. used for keeping specimens under observation
iii. used for magnifying specimens (1 MARK @ = 6)
iv. used for measuring liquids
v. used for holding chemicals during experiment
vi. used for holding test tube during heating

10. i. Enables transportation of cell requirements like oxygen and nutrients

ii. Ensures the removal of waste products from the cell to prevent its accumulation
iii. Helps in temperature regulation in the body
iv. Helps in transporting the hormones in the body (1.5@ = 6)
11(a).THE FOOD WEB
Mushrooms

Lizard frog
Cap:0.5, D: 1, lab: 2.5 MARKS = 4

Grasshopper bee butterfly

Hibiscus plant grasses

(b)i. lizard and frog (@ 0.5 = 1)

ii. mushrooms ( 1 MARK)

12.i. helps man to understand him/herself better

ii. Enables to answer fundamental questions (1.5 MARKS @ = 6)
iii. Helps people to enter into different careers
iv. Helps to conserve the environment for sustainable development

13.i. waterborne diseases are the diseases which are transmitted by contaminated water. 2MARK
ii. Examples of waterborne diseases that are affecting the digestive system are cholera and
typhoid. 2MARKS.
iii. Any three symptoms
-diarrhea, vomiting, stomachache (@ 1 MARK =3)

iv. Any three preventive measures (2 MARKS @ =6)

-boiling or treating boiling water
-washing hands with clean water and soap before and after eating and after visiting toilets.
-proper disposal of sewage
-good sanitation
. conclusion (2MARK)

14. i. transpiration is the process by which plants lose water through the stomata of the leaves in
form of water vapor. (1MARK)
ii. Three advantages (2 MARKS@ = 6)
-enables the loss of excess water from the plant
-helps in cooling the plant
 -enables absorption and distribution of water and mineral salts
iii. Two disadvantages (1 MARK @ = 2)
-may lead to wilting in the plant
-excessive rate of transpiration can lead to stunted growth
iv. Conclusion (1MARK)

15. i. classification is the process of grouping and sorting out living thing according to their
similarities and differences (1 MARK)
ii. Natural system of classification and artificial system of classification( 2MARKS)
iii. Three importance (2 MARKS @ =6)
-simplifies communication among the biologists
-makes the study of living things easy
-helps in identifying and naming new arising species
iv. Conclusion (1 MARK)

***********************************************************************
 FORM FOUR EXAMINATION - SERIES 02
MARKING SCHEME

1.
i ii Iii Iv V vi Vii viii ix X
E D A C B B A D D D
1@=10 marks
2.
LIST A I Ii Iii Iv v
LIST B E D C A B
1@=5 marks
3. a) 1@ Mark
i) Osmosis-Movement of water molecules from the region of high water potential to the region of
low water potential through a semi-permeable membrane.
ii) Double blood circulation—passing of the blood twice in the heart before completing one cycle.
b) i) 1. Xylem ………………1 mark
2. Phloem…………..1mark
ii) 1. Nucleus absent
2. Concave shaped any two, 1@mark.
3. Presence of haemoglobin

4. a) i) Respiration—process of releasing energy step-by-step……………1mark

ii) 1. Aerobic Respiration……….1/2 mark
2. Anaerobic Respiration……..1/2 mark
b) Thin, wet, blood supplied, ventilated………..1@ mark=4marks

5. a) any four (4) laboratory safety rules ..1@ mark=4marks

b) 1. To avoid accidents 2. To avoid confusion 3. To create awareness 4. To maintain
neatness……any two….1@ mark=2marks

6. (a) When bacteria will be eliminated no decomposition of dead organic matter will take
place, therefore the cycle of nutrients will not be completed.
(1 mark)
(b) The organisms in the food web which form a group of third trophic level are lion and hyena
0.5 @=1 mark)
(c) Secondary consumer are lion and hyena 0.5 @=1 mark)
(d) (i) Grass→zebra→lion→bacteria
(ii) Grass→zebra→hyena→bacteria
 (iii) Shrubs→gazele→lion→bacteria
(iv) shrubs→zebra→hyena→bacteria
(v) Grass→gazzele→lion→bacteria
(vi)Grass→gazzele→hyena→bacteria
(vii) Shrubs→gazzele→hyena→bacteria

(any 3 @ 1 mark=3 marks

7. (a) (i) mitosis – is a nuclear division which results into two daughter cells. 1 mark
(ii) Significance of mitosis: 3 mark
• Results into genetic stability because the daughter cells retain a similar number and type of
chromosomes as those of the parents.
• it is a mean of reproduction for binary fission
• it repairs body parts which have been damaged
• it used in the regeneration of body parts which have been cut off.

(b)(i)complete metamorphosis – this involve four stages. Example butterflies, housefly

mosquitoes. 1 mark
(ii) Incomplete metamorphosis – is the type of metamorphosis which involves three stages.
Example cockroaches, grasshopper 1 mark
(iii) ecdysis- the shedding of outer layer or covering of an organism example insects
1 mark

8. (a) (i) axial flowered plant was dominant, because after the cross all the F1 had axial flowers. 1
mark
(ii) 2 marks
Let AA – represent axial flowered plant
Tt – produces terminal flowered plant
Then the cross is

(iv) 2 marks
 Homozygous axial flowered plant
= 1/3 x312 = 104 plants

(b) Incomplete dominance – is the condition that arise when both allele containing a
characteristic is dominant and the aspect displayed by the organisms results from the partial
influence of both allele. 1 mark

9. a) Organic evolution—gradual changes in organisms over period of time……1mark

b) 1. Special Creation theory 2. Spontaneous generation theory 3. Steady-state theory 4.
Cosmozoan theory 5. Biochemical evolution theory………………….any three 1@=3marks
c) 1.Lamarckism and 2. Darwinism 1@mark

10. a) ½@ mark=2.5marks
1. Kingdom Monera 2. Kingdom Protoctista 3. Kingdom Fungi 4. Kingdom Plantae 5. Kingdom
Animalia.
b) ½@=3.5marks
Name of organism Group/ Kingdom
i) Mushroom Fungi
ii) bed bug Animalia
iii) liverwort Plantae
iv) Earthworm Animalia
v) Amoeba Protoctista
vi Bacteria Monera
vii. Maize Plantae

11. (a) Ways to minimize complications of the pregnancies

i. Visiting a prenatal clinic as early as possible once a woman discovers that she is
pregnant.
ii. Improving nutrition and maintain a balanced diet
iii. Prevent sexually transmitted diseases and cure them properly if contracted.
iv. Avoid giving birth at home especially when there is no certified and qualified midwife
(1@=4 marks)

(b) Causes of infertility.

i. Diseases especially STIs such as Chlamydia, gonorrhea and syphilis.

ii. Low sperm count this reducing chance of fertilization.
iii. Removal of the uterus for example due to cancer.
iv. Failure to ovulate because the ovaries are not producing eggs.
v. Low sperm motility that is the inability of sperms to swim and reach the eggs.
(any 2@1 mark=2 marks)
12. (a) Homeostasis – is the maintenance of constant internal environment in a living organisms.
1 mark

(b) To overcome overheating: - any 2 points (2 marks)

✓ moving to a shaded as lour place
✓ vasodilation
✓ Decrease metabolic rate.
✓ panting
✓ flattening of the hair erector muscles

13.
• Introduction--- Meaning of personal hygiene….2marks
• Importance……2marks
Improves personal appearance, to more acceptable and respectable, for good health, to be good
models for others…………any two 1@
• Principles……..6marks
Washing body every day, Wearing clean clothes, brushing teeth, Washing hands, cleaning
environment, keeping nails and hairs short, no sharing of personal items, use handkerchief or
tissue for covering mouth and nose, etc……….. any six 1@mark
• Items…
razor blade(nail cutter), A pair of scissors, soap, handkerchief/tissue, towel, tooth brush, hair
combs, tooth paste, hoes, bloom, iron box, hair cutting machines, etc….1/2@=4marks
• Conclusion….1mark
14. Main parts of the alimentary canal are ½@=3 Marks
i) Mouth,
ii) oesophagus,
iii) Stomach,
iv)Small intestine,
v) Large intestine and
vi) Rectum
Diagram 7marks
✓ Drawing (large, neat and relevant) 3marks
✓ labels any six ½@=3marks
✓ Caption 1mak
15. a) Table of results 6marks
Food tested Procedure(to be written in Observation ½@ Inference ½@
past tenses) 1@mark
Proteins NaOH +1% CuSo4 Purple color observed Proteins present

Starch Iodine solution Blue-black color observed Starch present

Lipids Sudan III solution Red droplets observed Lipids present

b) Water, Vitamins, minerals and roughages. 1@=4marks

***************************************************************
 FORM FOUR EXAMINATION - SERIES 03
MARKING SCHEME
1.
i ii iii iv v vi vii viii ix x
B D A C A A C B D B
1 marks @ Total 10 marks
2.
i ii iii iv v
I F C H A
1 marks @ Total 5 marks
3. (a) First is an immediate care given to a victim before taken to the hospital while First aid
Kit is a small box containing components for first aid (02 marks 1 each)
(b) (i)
a) It saves life
b) It brings hope and encouragement
c) It reduces pains of the victim
d) It prevents permanent disability
e) It prevents infections
f) It prevents fear of death
g) It shortens recovery period
h) It prevents excess blood loss (Any four ½ mark each)
(ii)
a) Calm and reassure and casualt and lay victim down
b) Support and immobilize the beaten area
c) To remove poison
d) Tie a wide elastic bandages along the limb
e) Wash the limb with soap and water to remove the venom around the wound
f) If breathing fails, start mouth to mouth ventilation
g) Take a victim immediately to hospital if possible (Any four ½ each)
4.
a) Gaseous exchange is the movement of gase (oxygen and carbondioxide) across
the respiratory surfaces (any four ½ each)
b) (i)
i. Cell membrane
ii. Trachea system
iii. Gills
iv. Gills
v. Stomata (½ each)
 b) (ii)
a) Physical exercise
b) Age
c) Concentration of carbondioxide and oxygen
d) Humidity
e) Concentration of Haemoglobin
f) Health status (Any three (01 mark each)

5. (a) i/ Excretion is the removal of waste products of metabolism form the body (½
mark)
ii/ (a) Removal of excess materials form the body
(b) Help in body cooling
(c) Removal of toxic materials form the body
(d) Regulation of body temperature (Any three ½ each)
(b) Because in the morning there is cold and no sweating as result excess water and
urea is taken out through kidney hence Urination in the morning is higher thin in
afternoon (04 marks)
6.
a)
Meiosis Mitosis
i. It results into four daughter cells i. It results into two daughter cells
ii. It results intoformation of haploid cells ii. It results into formation of diploid cells
iii. It occurs in reproductive cells iii. It occurs in somatic cells
iv. It involves two phases called meiosis I iv. It involves only one phase
and II v. No variation in offsprings (Any two 01
v. Variation occurs in offspings mark each)
b) Responsible sexual behaviours are those sexual behaviours that are accepted to the society
examples are Enacting laws and regulation, practice self control over temptation, abiding
by religious principles, teaching children good manners, avoid taking drugs while
irresponsible sexual behaviours are those behaviours that are not acceptable to the society
examples are Early marriage, Rape, Homosexuality, Abortion, Use of drugs (Abuse of
drugs). (04 marks 02 marks each)
7.
a) (i) Reflex action is a sudden automatic response due to a certain stimuli (½ marks)
(ii) Reflex arc is a path taken by reflex action or Reflex arc is nerve pathway taken by
nerve impulse between receptors and effectors (½ marks)
b.
Receptor cells sense the stimulifrom environment then sensory neurone the impulse to the
central nervous system. Relay neurone take nerve impulse to the brain or spinal cord for
interpretation and bring back the interpreted nerve impulses to the motor neurone where the
motor neurone take the information
- to effectors such as muscles or glands for responses. Explanation carries 1½ marks
Diagram = 1 mark Labeling = 2½ marks
8.
a) i/ Waste is the material that is no longer needed (½ mark)
ii/ (a) Recycling
(b) Re-using
(c) Reducing (1½ marks) ½ each
b)
i. Occurrence of diseases
ii. Environmental degradation
iii. Loss of biodiversity
iv. Provide bleeding grounds for vectors of disease
v. Produce bad smells (Any four 01 mark each)
9. (i) Rose plant with red petals with white spots be Rr (01 mark)
Parental phenotype: Rose plant with Rose plant with red
Red petals and X petals with white
White sports spots (½ mark)

Parental genotype: Rr X Rr (½ mark)

Meiosis ½ mark
Gametes: ½ mark
Fertilization: ½ mark R r R r
First filial generation ½ mark

(01 mark)
RR rr
Rr Rr
(ii) Genotypic ration
1:2:1 (01 mark)

10. (a)cord and non notochord

i. Multicellular (b)
ii. Reproduce sexually and asexually i. Oligochactae
iii. Posses nervous system ii. Dicotyledonae
iv. Have notochord and non notocord iii. Insect
v. Are mobile iv. Diplopoda
vi. Are heterotrophic v. Aves
vii. Posses excretory system vi. Mammals
viii. Posses digestive system vii. Cestoda (½ marks for each)
 11. When blood sugar raises (high glucose level) above 90mg per 100cm3 of blood, Islets
of Langerhans are stimulated to produce and release insulin hormone which converts
excess glucose in the blood stream into glycogen which later stored in the blood
stream is below 90mg per 100cm3 of blood, Islets of Langerhans stimulates to
produce and release glucagon hormone which converts stored glycogen from liver and
muscles into glucose back into the blood steam again (06 marks)

12. (a) Digestion is the breakdown of large food substance into simple food substances so as to
release energy in the body cells. White Egestion is the removal of undigestable and indigestible
substance form the body through anal pore (anus) (01 mark)
(b)
i.It is highly folded and coiled
ii.It is long of about 3 metres
iii.It is well supplied with networks of blood vessels
iv.It has micro villi and villi
v.It has numerous mitochondria
vi.It has thin epithelium membrane (Any five 01 mark each)

13. 1) Introduction (1½ mark)

(2) Points

Advantages
i. Used as decomposers
ii. Increase soil fertility
iii. Help in nitrogen cycle
iv. Help in digestion
v. Help in Vitamin synthesis
vi. Help in fermentation process
vii. Help in chemical manufacturing (Any three with explanation 02 marks each)
Disadvantages
i. Cause diseases and infections to plants and animals
ii. Cause food spoilage and decaying
iii. Some decreases soil fertility like denitriycying bacteria
iv. Cause water and fluid pollutions such as salmonera typhi and vibrio
cholera.
(Any three with explanation 02 marks each) (3) Conclusion (1½ marks)
14. (1) Introduction (01 mark)
(2) Conclusion (01 mark)
(3) Points

i. Natural selection iv. Variation

ii. Struggle for existence v. Speciation
iii. Survival for the fittest
vi. Isolation (Any four with explanation (02 marks each)
15. Causes – Corona Virus (01 mark)
Transmission
- Through air droplets by sneezing, coughing, breathing
- Through direct body contact by hand shaking, hugging, kissing (Any two 01 mark
each)
Symptoms and signs
- Dry coughing - Cold flue
- Short breath - Headache
- High fever - Body weakness
- Limbs pain (Any four ½ mark each)

Effects
- Lowering of body immunity
- Body weaknesses
- Death (Any two 01 mark each)

Prevention measures
- Wearing Barakoa (Masks)
- Avoid population in crowded area
- Avoid direct body contact like shaking hands, hugging
- Wash your hands frequency with clean water a soap
- Using of sanitizer (Any three 01 mark each)

**************************************************************
 ANSWERS
FORM FOUR EXAMINATION - SERIES 04
MARKING SCHEME

1. @ 1mark = 15marks
i. ii. iii. iv. v. vi. vii. viii. ix. x.
D B C B C A B C D D

2. @ 1mark = 05marks
i. ii. iii. iv. v.
D E A B B

SECTION B (60
Marks)
3. a). Is the special room designed for carrying out scientific
experiment. b) @ 1.5marks = 06 marks
i. Are usually substances containing microbes or other factors which
could cause disease

ii. Are substance which can cause death. eg: acid, alkali

iii. Are substance which can catch fire easily eg: alcohol
4. Grade total 06 marks
a) i). Moths, files, Dormice, Earthworms ( 01 mark @ 05 mark)
ii) Toads, shrews. (01 mark @ 0.5 marks)

b) 01 mark
Flowers Moths Toads Owls
Leaves Earthworms Shrews Owls
Rots Earthworms Shrews Owls
Berries Files Toads Owls
c) Source of energy/ food because they able to make their own food hence they are
producers (1.5 mars)
d) Earthworms will increase in number therefore there will be composition in the
resources (1.5 mark)
5. a) 04 marks (@ 1 mark)
Provide acid medium for rennin and pepsin
i. HCL
To kill microorganism
ii. Mucus prevent the wall of the stomach from being digested by enzymes
iii. Pepsin catalyses the conversion of proteins into peptides.
iv. Rennin coagulate (solidify) milk in young babies.
b) 02 marks (@ 1 mark)
i. If has secretory glands which produce digestive enzymes
ii. If has finger like projections called villi for the absorption of food.
iii. Long to ensure sufficient absorption of food.
iv. Large network of blood capillaries for transporting absorbed food to all parts of
the body.
v. If has thin layer of cells which allows easy diffusion of digested materials.
6. Grand total 6marks (@ 2 mark)
a) Above Biceps muscle/flexor muscle (01 mark)
Below Triceps muscles / extensor muscles (01 mark)
b) 2 marks (1mark @)
i. Biceps (Flexor muscle) contract while triceps relaxes
ii. Biceps relaxes while trips contract
c) 2 marks (1mark @)
Posses muscle fibres which can contract and relax to allow movemen
Store oxygen which can be used during vigorous exercise
Posses abundant mitochondria which help in providing
energy required for contraction of muscles.
Well supplied with blood capillaries
7. (a) 04 marks (01 mark @)
Conditioned reflex action Simple reflex action
i. An action that is learned through exercise i. A rapid automatic action is inborn
or experience
ii. Occurs with ones awareness through ii. Occurs very rapidly without one’s
training or exercise conscious being involved.
iii. Two or more combined stimulus are iii. A response is brought or initiated by
exercise stimulus which is related.
iv. The brain is involved directly during a iv. It does not directly involve the brain
conditioned reflex action. .

(b) Because the nasal passages inflamed and coated with mucus, the smell receptors
are essentially non-functional. (02 marks)
8. Grand total 06 marks
i. Adrenaline hormones. ( 1.5 marks)
ii. 4.5 marks (1.5
marks@)
Increasing metabolic rate
Increase heartbeat
Diverting the blood to the vital organs.
9. Grand total 06 marks.
a) Germination ; Is the process by which the seed develops into seedling
(young plants)
Seed; Is a small embryonic plant enclosed in a covering called
testa. b) 01 mark (0.5 mark @)
i. Hypogeal
germination ii.
Epigeal germination
c) 4 marks (01 mark @)
The seeds absorbs water through micropyle and enlarge.
The testa bursts and radical continues to elongate and give rise to
many roots.
As the radical elongated it pushes the seeds out of the ground.
The plumule emerges, at the stage, the young plant is called a seedling.
10. Grand total 06 marks
a) 1.5 marks (@0.5 mark)
i. Heterozygous
ii. Homozygous (dominant)
iii. Homozygous (recessive)
b) 4.5 marks
• No sex determination of the child is by chance (0.5 mark)
• There are two sex chromosome X and Y that determine sex of a child. (1 mark)
• Male carries XY and female carries XX chromosomes. (1 marks)
• Sperm (male gametes) has either X or Y chromosomes while ovum (female
gametes) is always an X chromosomes. (1marks)
• The sex of the child is a matter of chance depends on either sperm with Y
or X chromosome fertilize an ovum. (01 mark)
• XX female child XY male Child. (01 mark)
11. Grand total 6 marks
a) Is the scientific system of naming organisms where by every name is made
up of two Latin words. ( 01 mark)
b) 3 marks (@ 1mark)
i. Scientific name should two parts; genus and
species. ii. The generic name is written before the
specific name iii. The generic name must start with a
capital letter.
iv. The specific name is written by small letters
v. In publishing document such as books, scientific name should be
written in Italics when hand written or typed, the names should be
underlined.
c) 02 marks (@ 1 mark)
i. Simplify communication
ii. Remove ambiquity ie; organism is known by a single
name.
12. Grand total 6 marks (1.5 marks @)
Sweating
Panting
Vasodilatation and vasoconstriction
Shivering
Increase or decrease in metabolic rate
Behavioural regulation eg; animal searching for shade to cool down or a
person putting on more clothes to worm up.
13. Introduction
The students should explain the breast feeding and the bottle feeding in short
Breast feeding is a complex diet in itself because it contains all the nutrients
the baby needs.
Bottle feeding is a practice where a baby is fed on milk other than that of
the
mother. It usually involves the use of bottle with a teat and the milk used is either
fresh from an animal or an artificial milk formula such as lactogen. (2 marks)
Mainbody
The advantages of breast feeding are (any six points 2marks@)
i. Breast milk, especially the colostrums produced in the first few days
after birth protect the baby from infections.
ii. Breast milk is safe and will not introduce infection unless the mother is
sick iii. Breast milk provides a balanced diet for the baby.
 iv. Breast milk is the vight temperature and does not require heat.
v. Breast feeding does not require complicated preparations, such as those
used in bottle.
vi. Feeding the mother is just required to wash her hands and breast
before sucking the baby.
vii. Breast milk can protect the baby from developing
obesity. viii. Breast milk can protect a baby from
developing allergies.

14. Introduction
Breathing is the process of drawing air into and out of the lungs. The drawing of air
into the lungs is called inspiration/inhalation and the drawing the air out of the lungs is
called expiration/exhalation.
Main
body
The students should explain the inhalation and exhalation
process.
During inhalation the muscles of the diaphragm contract hence flattens out the
diaphragm. In the mean time the intercostals muscles contract which cause the ribs and
breast bone to be raised upward and outwards. The flattening out of the diaphragm the
upward and outward movement of the ribs and breast bones increase the volume of
chest capacity. As soon as the pressure in the chest capacity is reduced, air is drawing
into the lungs through the nose, trachea bronchi and bronchioles. (4 marks)
During expiration process the muscles of the diaphragm and intercoastal
muscles relax, the ribs and breast muscles move down and inward under their own
weights. As they move they tend to push the relaxed diaphragm downwards, the
movement make the diaphragm dome shaped. The pushing of the diaphragm
upward, the downwards and inwards movements of the ribs and breast bone reduce
the volume of the chest capacity. This increase the pressure in the chest cavity thus air
is forced out of the lungs. (4marks) Conclusion
15. (a)
STL s – Sexually transmitted infections
STDs – Sexually transmitted diseases
HIV – Human Immunodeficiency Virus.
AIDS – Acquire Immune Deficiency Syndrome.
(b) Risk situations, beahaviour and practice ( 4 points, mention 1mark, explain 1mark
=
10 marks)
Sexually intercourse with an infected person
Blood transfusion from the infected donor
Organ transplant form infected donor
Infected mother to the child during birth or breast feeding.
Using unsterilized surgical or piercing instruments such as needle, razor
blade.
Sharing tooth brush, underwear with infected person

Conclusion
 ANSWERS
FORM FOUR EXAMINATION - SERIES 05

MARKING SCHEME

1) 01 mark @ = 10marks
ITEM i ii iii iv v vi vii viii ix x
ANSWE C C B C B C C E C C
R

2) 01mark@ = 05marks
LISTA i ii iii iv i
LIST B E I H C B

3) (a) microscope is a scientific instrument used to magnify very small

specimen/object so that their details can be seen clearly 𝟎𝟏𝒎𝒂𝒓𝒌𝒔
(b) (i) Stage is the surface on which the specimen is place for closer
observation
(ii) Diaphragm is the part that regulate the amount of light passing from
the mirror to the condenser
(iii) Stage clip to hold the slide containing specimen in place
(iv) Body tube is the part that support the eyepiece and the rotating
nosepiece.
(v) Mirror is the parts that reflects and direct light to the specimen under
observation 𝟎𝟏𝒎𝒂𝒓𝒌@ = 𝟎𝟓𝒎𝒂𝒓𝒌𝒔
4) (a) (i) Ribosome
(ii) Nucleus
(iii) Cell membrane
(iv) Mitochondria 𝟎𝟏𝒎𝒂𝒓𝒌@ = 𝟎𝟒𝒎𝒂𝒓𝒌𝒔
(b) This statement is not true because cell is the basic unit of life and nucleus is
the one which control all activities of the cell therefore life is only possible in a
nucleated cell and not other wise 𝟎𝟐𝒎𝒂𝒓𝒌𝒔

5) (a) (i) Reduce the amount of waste production for example we can use woven
bag for shopping instead of buying plastic bag that cannot be used for long period
of time
(ii) Re-use of items for other purpose instead of throwing them away to
increase waste on the environment. For example we can used the bottle of
Kilimanjaro drinking water for storing oil, milk etc

(iii) Recycling is the process of returning some waste materials so that they
can be changed into other products. For example broken glass can be melted and
used to make new glass bottles. (𝟎𝟏𝒎𝒂𝒓𝒌@ = 𝟎𝟑𝒎𝒂𝒓𝒌𝒔)

(b) (i) Wash your hands with soap and clean water before the meal
(ii) Serve yourself a reasonable portion of food
(iii) Remember to pray for food or wait for someone to pray
(iv) Chew food properly with your mouth closed and avoid talking with
food in the mouth
(v) Avoid discussing things that could make other people loose appetite
and criticizing the food prepared by other people
 (vi) Do not waste food; finish what you have on your plate
(𝒂𝒏𝒚 𝟎𝟑 𝒑𝒐𝒊𝒏𝒕𝒔 𝟎𝟏𝒎𝒂𝒓𝒌@ = 𝟎𝟑𝒎𝒂𝒓𝒌𝒔)

6) (a) Duodenum 𝟎𝟑𝒎𝒂𝒓𝒌𝒔

• Protein
• Starch
• Lipid 𝟎𝟎½𝒎𝒂𝒓𝒌@ = 𝟎𝟏½𝒎𝒂𝒓𝒌𝒔
(b)
Food nutrient Enzyme involved Favorable condition
Protein Pepsin (00½mark) Acidic condition that is HCL
(00½mark) (00½mark)

7) (a) (i) oxygen dept.is the extra amount of oxygen required by the body to
remove accumulated lactic acid in the muscle when the body is at rest.
(𝟎𝟏𝒎𝒂𝒓𝒌𝒔)
(ii) In muscle cells: Glucose Lactic Acid + Energy
(𝟎𝟐𝒎𝒂𝒓𝒌𝒔)
In bean plant cells Glucose Alcohol + Carbon dioxide Gas
+ Energy

(𝟎𝟐𝒎𝒂𝒓𝒌𝒔)
(b) The red blood cells increase in number at high altitude with less oxygen so
that more oxygen can be transported so as to enable efficient respiration and
provision of sufficient energy for the individual. At high altitude pressure is lower
thus lowers oxygen availability. (𝟎𝟏𝒎𝒂𝒓𝒌𝒔)
8) (a) (i) White blood cells serve a roll of destroying disease causing
microorganisms like bacteria. They do this through phagocytosis or release of
antibodies
(ii) Matured red blood cells lacks nucleus so as to provide more room for
hemoglobin which transport respiratory gases such as oxygen and carbon dioxide
within the body
(iii) Vein had a valve at a regular interval. Veins has a large lumen and
transport blood under low pressure towards the heart therefore the valves close
temporarily to prevent back ward flow of blood and create minimum pressure that
push blood towards the heart (𝟎𝟏𝒎𝒂𝒓𝒌@ = 𝟎𝟑𝒎𝒂𝒓𝒌𝒔)
(b) (i) It has narrow/ small lumen to create pressure
(ii) It has a thick muscular wall to withstand high blood pressure
(iii) It is elastic to contract and relax to create pulse(𝟎𝟏𝒎𝒂𝒓𝒌@ =
𝟎𝟑𝒎𝒂𝒓𝒌𝒔)

9) (a) (i) Reflex action refers to an autonomic response taken towards the
stimulus. It do not involve brain directly means that it is under control of spinal
cord. Example removal of hand quickly when touching hot object. 𝟎𝟏𝒎𝒂𝒓𝒌
(ii) Receptor Sensory neuron Intermediate neuron Motor neuron
Effector organs (𝟎𝟎½𝒎𝒂𝒓𝒌@ = 𝟎𝟐½𝒎𝒂𝒓𝒌𝒔)
(b) (i) Thyroxin hormone
(ii) Somatotrophin hormone/Growth hormone
(iii) Insulin hormone
(iv) Aldosterone hormone
(V) Oxytocin hormone (𝟎𝟎½𝒎𝒂𝒓𝒌@ = 𝟎𝟐½𝒎𝒂𝒓𝒌𝒔)

10) (a) (i) Incest is the sexual practice/act between the close related individuals.
For example father and his daughter, brother and his sister, mother and her son etc
 (ii) Homosexuality is the sexual practice between the individual of the
same sex. That is male and male individuals (gays), female and female (lesbians)
(iii) Prostitution is the sexual deviation where by someone uses his/her
body as a source of income. For example commercial sexes workers in the city
(iv) Masturbation is the sexual practice where by an individual stimulate
his or her Sexual organ to attain sexual gratification/desire (𝟎𝟏𝒎𝒂𝒓𝒌@ =
𝟎𝟒𝒎𝒂𝒓𝒌𝒔)

(b) Identical twins are the individuals result when one egg is fertilized by single
sperm and divide into two parts after fertilization. They are expected of the
same sex and same genetic materials. WHILE fraternal twins result when two
eggs are fertilized by different sperm. This individual can either be of the same
sex or different sexes and they are genetically different
(𝟎𝟐𝒎𝒂𝒓𝒌𝒔)

11) (a) The rate of growth during adolescence is rapid simply because the rate of cell
division is higher than the rate of cell death. In this stage new tissues are formed
due to rapid cell division.

(b) DIAGRAM OF SIGMOID GROWTH CURVE SHOWING FOUR

SIGNIFICANT PHASES

A B C D
GROWTH

TIME IN DAYS

KEY: A--- Lag phase: period of slow growth 𝑪𝒂𝒑𝒕𝒊𝒐𝒏 = 𝟎𝟏𝒎𝒂𝒓𝒌

B--- Log phase: period of rapid/exponential growth
𝑫𝒊𝒂𝒈𝒓𝒂𝒎 = 𝟎𝟏𝒎𝒂𝒓𝒌
C----Linear phase: period of decelerating growth
D--- Stationary phase: period of no further growth 𝑳𝒂𝒃𝒆𝒍𝒊𝒏𝒈 = 𝟎𝟎½@ = 𝟎𝟐𝒎𝒂𝒓𝒌𝒔

12) a) Mendelian first law state that “An organism’s trait is controlled by the pair of
factor called gene but only one factor of that pair is represented in a single gamete
during meiosis
b) let’s “A” represent normal skin colour 𝟎𝟎½𝒎𝒂𝒓𝒌
let’s “a” represent albinism character 𝟎𝟎½𝒎𝒂𝒓𝒌
 let’s characters occur in pairs that can be segregated during gamete formation

𝑃𝐴𝑅𝐸𝑁𝑇𝑆: Phenotype: 𝑁𝑂𝑅𝑀𝐴𝐿 𝑀𝐴𝐿𝐸 X 𝑁𝑂𝑅𝑀𝐴𝐿 𝐹𝐸𝑀𝐴𝐿𝐸 𝟎𝟎½𝒎𝒂𝒓𝒌

Genotype: 𝐴𝑎 𝐴𝑎 𝟎𝟎½𝒎𝒂𝒓𝒌
meiosis 𝟎𝟎½𝒎𝒂𝒓𝒌
𝐴 𝑎 𝐴 𝑎
𝟎𝟎½𝒎𝒂𝒓𝒌
gametes

𝟎𝟎½𝒎𝒂𝒓𝒌
fertilization

offspring 𝐴𝐴 𝐴𝑎 𝐴𝑎 𝑎𝑎 𝟎𝟎½𝒎𝒂𝒓𝒌

Conclusion: According to the genetic crosses above both parents were responsible
for an Albino child as they are carrier of albinism character although both of them
Were phenotypically normal because albinism is controlled by recessive gene
(𝟎𝟐𝒎𝒂𝒓𝒌𝒔)
13) cholera is an acute intestinal disease characterized by sudden onset of profuse
watery stool, vomiting, rapid dehydration and circulatory collapse.
(𝟎𝟏𝒎𝒂𝒓𝒌)
Cholera is caused by bacteria known as “𝒗𝒊𝒃𝒓𝒊𝒐 𝒄𝒉𝒐𝒍𝒆𝒓𝒂” (𝟎𝟐𝒎𝒂𝒓𝒌𝒔)

Cholera is transmitted through oral faecal route by:

• ingestion of contaminated food
• ingestion of contaminated water
• ingestion of cysts in faecally contaminated food or water
(𝒂𝒏𝒚 𝟎𝟐 𝒑𝒐𝒊𝒏𝒕𝒔 𝟎𝟏𝒎𝒂𝒓𝒌@ = 𝟎𝟐𝒎𝒂𝒓𝒌𝒔)

Sign and symptoms of cholera:

• low grade fever

• profuse watery stool (rice water) followed by faecal matter
• vomiting
• dehydration
• decrease of blood pressure
• loss of body weight
• muscle cramp
• breathing fast and shallow
• body weakness (𝒂𝒏𝒚 𝟎𝟐 𝒑𝒐𝒊𝒏𝒕𝒔 𝟎𝟏𝒎𝒂𝒓𝒌@ = 𝟎𝟐𝒎𝒂𝒓𝒌𝒔)

effects and complication of cholera:

• malnutrion
• severe acidosis
• shock due to ℎ𝑦𝑝𝑜𝑔𝑙𝑦𝑎𝑐𝑎𝑒𝑚𝑖𝑎
• weight loss (𝒂𝒏𝒚 𝟎𝟐 𝒑𝒐𝒊𝒏𝒕𝒔 𝟎𝟏𝒎𝒂𝒓𝒌@ = 𝟎𝟐𝒎𝒂𝒓𝒌𝒔)

preventive measures of cholera:

 • wash your hands after visiting the toilet and before eating
• boil and treat drinking water
• consume hot food
• wash fruits and vegetables before eating
• food should be well cooked and kept covered all the time
• proper environmental hygiene especially toilet
• all bucket latrines and pit latrines should be kept covered at all times t
prevent houseflies settling on feaces
• manure heaps, animal houses and latrines should be as far as possible
from living room and house (𝒂𝒏𝒚 𝟎𝟑 𝒑𝒐𝒊𝒏𝒕𝒔 𝟎𝟏𝒎𝒂𝒓𝒌@ =
𝟎𝟑𝒎𝒂𝒓𝒌𝒔)

treatment of cholera: Administer antibiotics according to the culture and

sensitive to combat infection such as:

✓ 𝑇𝑒𝑡𝑟𝑎𝑐𝑦𝑐𝑙𝑖𝑛𝑒 given as single dose of 2g

✓ 𝐷𝑜𝑥𝑦𝑐𝑦𝑐𝑙𝑖𝑛𝑒 300mg as a single dose
✓ 𝐸𝑟𝑦𝑡ℎ𝑟𝑜𝑚𝑦𝑐𝑖𝑛 40mg/kg daily in 3 divided dose for 3 days
✓ 𝐶𝑜𝑡𝑟𝑖𝑚𝑜𝑥𝑎𝑧𝑜𝑙𝑒, 2 tablets twice daily for 3 days for adult in good alternative
(𝒂𝒏𝒚 𝟎𝟐 𝒂𝒏𝒕𝒊𝒃𝒊𝒐𝒕𝒊𝒄𝒔 𝟎𝟏𝒎𝒂𝒓𝒌@
= 𝟎𝟐𝒎𝒂𝒓𝒌𝒔)
Conclusion: (𝟎𝟏𝒎𝒂𝒓𝒌𝒔)
14) Communicable diseases are the diseases transmitted from one person to another
i. Through air. Eg flue, turberculosis asthma 𝐶𝑂𝑉𝐼𝐷 19 etc
ii. Through sexual intercourse. Eg AIDS, gonorrhea, syphilis, candidiasis etc
iii. Through contaminated water and food. Eg cholera and typhoid
iv. Through blood transfusion. Eg AIDS,malaria, hepatitis b etc
v. Through vector. Eg malaria, sleeping sickness, plague etc
vi. Through contact. Eg 𝐶𝑂𝑉𝐼𝐷 19, scabies, ringworms etc
𝑴𝒆𝒏𝒕𝒊𝒐𝒏𝒆𝒅 𝒑𝒐𝒊𝒏𝒕 𝟎𝟏𝒎𝒂𝒓𝒌@ = 𝟎𝟓𝒎𝒂𝒓𝒌𝒔
𝑬𝒙𝒑𝒍𝒂𝒊𝒏𝒂𝒕𝒊𝒐𝒏 𝟎𝟎½𝒎𝒂𝒓𝒌@ = 𝟎𝟐½𝒎𝒂𝒓𝒌𝒔
𝑨𝒏𝒚 𝟎𝟏 𝒆𝒙𝒂𝒎𝒑𝒍𝒆 𝟎𝟎½@ = 𝟎𝟐½𝒎𝒂𝒓𝒌𝒔
𝑻𝑶𝑻𝑨𝑳 = 𝟏𝟎𝑴𝑨𝑹𝑲𝑺

15. Oxygen molecules from the atmosphere enters the body through nostril, nasal cavity,
pharynx, glottis, larynx, trachea, bronchus, bronchioles, alveolus duct and finally to the
alveolus sac where exchange of gas takes place. Once the oxygen molecule enters the
alveolus, the concentration of oxygen molecules increases therefore the molecules diffuse
out the alveolus sac into the blood capillaries surrounding it. In the blood capillaries
oxygen molecules combine with haemoglobin to form unstable compound called
oxyhaemoglobin which is transported through the blood to the liver tissues. Once reach the
liver tissues, oxyhaemoglobin break down and set free molecules of oxygen which then
diffuse out of the blood capillaries into the liver tissues for respiration.

𝑨𝒏𝒚 𝟎𝟓 𝒃𝒐𝒍𝒅𝒆𝒅 𝒑𝒐𝒊𝒏𝒕 𝟎𝟐𝒎𝒂𝒓𝒌𝒔@

𝑻𝑶𝑻𝑨𝑳 = 𝟏𝟎𝑴𝑨𝑹𝑲𝑺
 ANSWERS
FORM FOUR EXAMINATION - SERIES 06

MARKING SCHEME
1.
Qn i ii iii iv V vi vii Viii ix x
Ans A D B B B E A C B A

1 Mark@ total 10Marks

2

LIST A I ii iii Iv v
LIST B B A C H F

1 mark @ = 05marks.

3. (a) (i) Biology Laboratory-Is the special room or place where Biological experiments
areconducted.

(ii) Botany-Is the branch of Biology which deals with the study of plants
1mark@=2marks

(b) (i) Mirror-Reflect and Direct light to the observation underobservation

(ii) Objective Lens-Magnifies the specimen underobservation
(iii) Eye Piece-Has lens which magnify specimen either five times (x5) or ten times(x10) etc
(iv) Base-support themicroscope
(v) Limb or Arm-Support the body tube, knobs, stages, diaphragm, and mirror also used for
carrying the wholemicroscope
(vi) Clip-Holds the slides containedspecimen
(vii) Course Adjustment-Raise and lower the body tube in order to bring image into the focus
(viii) Stage-surface on which the specimenisplaced. 0.5mark@=4marks

4. (a) (i) Water

• Carbonidioxide (0.5mark@=2Marks)
• Chlorophyll
• Sunlight
(ii) Glucose or carbohydrate any one point 1 mark

• Water
• Oxygen0.5mark@=1Mark
(b) Adaptive features ofileum

i. It has finger like project called villi. It increase the surface area for theabsorption of food
ii. Its very long has large surface area for the absorption of soluble productof digestion
iii. Have a large network of bloodcapilarites
iv. That transport absorbed food to all parts of the body
v. Its folded
This increase surface area that is in contact with food (any 3 point 3 marks) each
point 0.5mark@=2.5Marks
5. (a) A zygote is a diploid nucleus formed by a fusion of the male and female gamete
Where as a sperm is a male reproductive cell. it is a haploid cell.1marks@=2marks

(b) (i) Oxytocin hormone

(ii) Prolactinhormone
(iii) Anti-diuretic (Vasopressin) hormone
(iv) Aldosterone hormone1mark@=4Marks.

6. (a) epigeal germination-Is the kind of germination in which cotyledon brought abovethe
soilsurface.While ------ (01)

Hypogeal germination-Is the kind of germination in which the cotyledon remains inthe
soil ---- (01)

(b) condition necessary for seedgermination

(i) Air (oxygen) (ii) water (iii)suitabletemperature ------- (0.5mark@ total 1.5)

(c) -Germination is the process where a seed developsintoseedling ---- (01marks)

• Seed absorb water through small hollow called micropyle and swell, then the food
stored in the cotyledon are then converted into energy by respiration of glucose forthe
development of embryo, The seed split and plumule grow up wards while radicle
growdownwards -------- (01marks)

7. (a) (i) Genetics-Is the branch of biology which deals with the study of heredityand
variations inorganisms.

(ii) Albinisms-Is the condition in which the body being unable to makemelanin

(iii) Complete Dominance-Is the condition in which a dominant gene completelymasks

the recessivegene.

(iv) Mutation-Is the sudden change of genetic materials .0.5mark@=2Marks

(b) Let A-normal person

a-albino

Parental genotypes.Mrmsakanjia be-Aa ,Mrsmsakanjia be -Aa

 Parental genotypes.MrMsakanjia be-Aa ,MrsMsakanjia be –Aa4marks

8. (a) (i) Red blood cell-Used to transport oxygen gas in the body.(021marks)

(ii)White blood cell-Protect the body against infections. (01marks)

(b) Functions of Blood in Human being

(i) It transports nutrients from the ileum to the other parts of thebody

(ii)It transports oxygen from the lungs up to other parts of thebody

(iii) It distributes heat in thebody

(iv) It transports hormone from endocrine glands to the site they arerequired

(v) It distributes white blood cells and antibodies in whole thebody

(vi) Protect the body though the white body cells. any six point=6marks
9. (a) Osmoregulation is the process of controlling the concentrations of mineral saltsand
water content in the body(2marks)

(b) Mechanism of regulating sugar level in theblood

• The level of glucose in the blood is controlled pancreas which plays an important role
in maintaining constant level of glucose in theblood.
• The pancreas produces two hormones: which are glucagon and insulin. Thosetwo
hormones are antagonistic that is they work together but in opposite directions to
make sure that the level of sugar stays near 90mg/100ml in humanblood.
• If there is high level of sugar in the blood insulin convert an excess sugar into
glycogen and if there is low level of sugar in the blood, glucagon breakdownthe
stored glycogenintoglucose. (6marks)
10. (a) (i) Teas-can killbacteria---(0.5mark)

(ii) sweat on the hand-Act as barrier to bacteria to enter in the body throughthe
skin—(0.5mark)

(iii) on the bronchus-Exhalation process remove bacteria together withair----

(0.5mark)

(iv) In the stomach-Hydrochloric acid produced by gastric gland destroythe

bacteria --(0.5mark)

(b) (i) It is not health sleep in a closed room with many potted plants, because at nightplants
uses oxygen for respiration process and because of that a person will compete for
oxygen in the room withpottedplants ----- (02marks)

(ii) It is dangerous to sleep in a poorly ventilated room with a charcoal burner on because
the burning charcoal uses oxygen available and produce carbon monoxide. Thecarbon
monoxide has high affinity to haemoglobin than oxygen, then when carbon monoxide
and haemoglobin combine they form a stable compound carboxyhaemoglobin which
can not be broken down to release oxygen, hence transported of oxygen in the body
will be prevented. The person will suffer from lack of enough oxygen inthe body,
--------------------------------------------------------------------------- (02marks)

11. (a) Food chain is the flow of energy from the producer to consumers and food web is a
network of food chain2marks.

(b)

4 mark
Sexual and Asexualreproduction
1. Sex cell are involved No sex-cell involved
2. Two parental organism we involved One parent is involved
3. The new organism is genetically
different from each of its parent The daughter organism are genetically
identical to their parent
4 Slow growth process rapid growth process
(4 marks of any four point)
13 (a) Reasons to the failure to eradicate cholera in thecountry

- Most citizens in the country do not use clean and safe water fordrinking---02

- Most citizens in the country are living inunhygienic conditions ----02

- The sewage transportation system in the urban are problem especially duringrain
season, most these systemareblocked --- 02

- The improper uses of pit latrines inruralarea ---- 02

-Shortage of knowledge (poor education) about person andcommunityhygiene ---- 02

(b) The disease can be eradicated successfully by the followingways

- Proper preparation of food in hygienic condition

-Boil and filter the drinking water and keep it in cleaned container

- Wash the fruits with warm water to eliminatecontaminations

_ Wash hand with cleaned water and soap after visiting toilets

-Eating hot food, people should avoid eating cold food

- Seek medical treatment and vaccinations soon as theyinfected

Any five @1, total 05

14 (a) Food preservation-is the process of treating foodstuff with some materials to make
food to last forlongtime -----à01

-the materials used to preserve food are added to food in order to slow down microbial
activities

(b) Local (traditional)food preservationmethods

- Drying-In this method moisture are removed from the food(dehydrationmethod)

- Salting-salts absorb water from foodstuff and killmicrobials

- Smoking-This method remove moisture from the foodstuff egFishes

-Curing-Is the method where food is hung over charcoal fire and smoke-this kill
most bacteria Any 4 points @ 1marks

(c)Advantages Local (traditional) food preservationmethods

- No chemicals are added to the food materials hence the food remainsnatural

- It is not expensive because does not need much cash(many)

-The food is preserved for a long time

- The preserved food can be traded in longdistances

-Food is easily accessed in the time ofitsshortage Anye 4 points @

1marks Conclusion (01marks)

15. Mechanism of gaseous exchange on alveolus with the aid of diagram

Actual gaseous exchange on of oxygen and carbon dioxide occurs in the alveolus

The alveoli are surrounded by the network of blood capillaries. When breathing in air
with high concentration of oxygen gas accumulates in the alveoli than in the blood
stream; this causes oxygen gas to diffuse out of the alveoli into the blood in the
capillaries where if combine with hemoglobin to form Oxyhaemoglobincomplex which
the transport oxygen gas to the tissue 01 mark

At the tissues the oxyhaemoglobin breaks and release oxygen and haemoglobin. The
tissues uses oxygen and release carbondioxide gas 01 mark

Production of CO2 (g) by the tissues causes the rise in the level of CO2 (g) in the tissues
than in the blood 01 mark

CO2 (g) then diffuses into the blood stream where it combine with haemoglobin to form
carbominohaemoglobin 01 mark

The capillaries transport CO2 (g) in this form to the alveoli.

The concentration of CO2(g) higher I the blood at this movement than in the air in the
alveoli and hence cause diffusion of CO2 (g) from the blood into the alveoli. CO2 (g) is
then transported to the atmosphere through bronchioles, glottis, pharynx and finally
nostrils. 5marks

Diagram of alveolus showing O2(g) and Co2(g) exchanges (01 mark

for heading 04 marks for thesketch
 ANSWERS
FORM FOUR EXAMINATION - SERIES 07

MARKING SCHEME

1. @ 01 MARK = 10 MARKS

i ii iii iv v vi vii viii ix x

D C C B B D E B B C
01 Mark @= 10 Marks
2.

i ii iii iv V
B D F H J
01 Mark@ = 05 Marks
3.
a) (i) First aid kit;
Is a small box which keeps medications and equipments used in providing first aid (01
Mark)

(ii) Risks; Are actions or behaviors which can results to harmful consequences to the life of
health of person (01 Mark)

(iii) An accident; Is an unexpected event which may lead to injury to a person (01 Mark)

(iv) Poisoning; Is an occasion when a person or animal consumes or inhales a substance

which will harm his or her body (01marks)
Total = 06marks

b) First aid to a Halima’s son who has been string by a honey bee
i. Remove the string by scrapping gently using a blunt object such as a plastic card. Do
not use your fingers or a sharp object because this will make the string to release
more venom into the body (001/2 marks)
ii. Wash the stung area with soap and water (001/2 marks)
iii. Apply baking soda paste on the area (Use ratio of 1 tea spoon of water to 3 tea spoon
of baking soda). The sting is acidic, baking soda is is a base and so it neutralizes the
acid (001/2 marks)

iv. Apply a cold compression on the affected area to relieve pain and swelling. If the
victim develops the allergic reactions for example nausea, diarrhea, dizziness or
swelling of the lips or throat, take the person to hospital immediately (001/2 marks)
 4.
a) Condition necessary for seed germination
i. Water;
The role of water in the seed germination hydrolyzed food substance to
release energy.
▪ Act as a medium for all enzymes activities
▪ Also help to soften the testa / hard coat so as to allow radical and
plumule to emerge

ii. Optimum temperature;

The role of temperature is to activate the respiration. As temperature increase
to optimum point also increase the rate of enzymes activities for respiration

iii.Oxygen; The role of oxygen is required by cell for respiration. For cell
division and growth, as energy is available, the cell increase in size and ready
for division
Mentioning = 001/2 marks, Explanations= 01 marks
011/2 Marks @ = 041/2 Marks
b) Difference
EPIGEAL HYPOGEAL
i) Is a type of germination where by seed coat / i) Is a type of germination where by seed coat/
testa comes above the ground testa remains underground
ii) Hypocotly is long and appear first and ii) Hypocotly is short and not curved
is curved to protect plumule
iii) Epicotly is short iii) Epicotly is long
iv) Energy comes from cotyledons iv) Energy comes from endosperm

v) Example; Occurs in Bean seed and v) Example Occurs in coconut, pea and maize
castor seed grain
Any 2 points, @001/2 marks, Example in each 001/2 marks,
Total 011/2 marks,
TOTAL= 06
Marks
5. a) Characteristics of Arthropods (Phylum Arthropoda)
i. They have jointed appendages/legs
ii. They have segmented bodies
iii. They have exoskeleton Any 02 points@00½ mark= 01 mark

b) (i) Classes of Phylum Arthropoda

• Class crustacea
• Class Diplopoda
• Class Insecta 05points @001/2 marks = 021/2 marks
• Class Chilopoda
• Class Arachnida

(ii) Class Representative member(s)

• Class crustacea Crabs, Lobster, Prawns
• Class Diplopoda Millipede
• Class Insecta Butterfly, Grasshopper, Housefly
• Class Chilopoda Centipedes
• Class Arachnida Spider, Scorpion
Any 01 example @001/2 marks = 021/2 marks
 TOTAL=06 Marks

6. a).
(i) Life style such as smoking, Lack of exercise, Stress and taking alcohol also put one in danger
of developing heart problems such as coronary heart disease and high blood pressure.

- Diet, Eating food with higher level of cholesterol and fats causes narrowing of blood vessels,
due to deposition of fats in blood vessels, resulting to stroke, high blood pressure
(Hypertension) and coronary thrombosis (diseases) 02 marks

ii) The heart must beat faster during the exercise because by increase the heart rate, the body is
able to increase the cardiac output and deliver the necessary blood flow to the muscles and
other body parts.

- During exercise, the body’s muscles increase their activities level and consume more
oxygen to supply energy for muscles contraction and relaxation 02marks

b) When a ring of bark is removed from the tree it dies because phloem tissues are destroyed
hence translocation of food from the leaves to parts below the ring is blocked.
02marks

TOTAL= 06 Marks

7 a) Adaptation of lungs Alveoli

• Have thin membrane to facilitate quick diffusion
• They are moist for easier gases diffusion
• They have large surface area to volume ratio for maximum exchange
• They are well supplied with blood capillaries for transportation of gases
• They have mucus and surfactants to lower surface tension
Any 04 Points @001/2 marks =02marks

b) 4 factors affecting rate of respiration

• Temperature
• Activity
• Size of an organism
• Age Any 04 Points @001/2 mark=02marks
• Health of an organism

c) (i) Plants - Energy (2ATP) and alcohol (01Mark @001/2 marks)

(ii) Animal - Energy (2ATP) and Lactic acids (01Mark @001/2 marks)
TOTAL=06 Marks

8. a)
(i). Natural Environment
Is made up of all living and non living things that occur naturally on earth, that is not man
made or acted by man (001/2 marks)

(ii). Ecosystem
Is the natural unity containing or made up of communities of living things (biotic) and non-
living things (abiotic) whose interactions leads to a safe sustaining system (001/2 mark)
b)
(i) Components of an ecosystem and their function
✓ Producers
Role; They are most green plants which produce food
 ✓ Consumers
Role; Organism which feed on other organisms
✓ Decomposers
Role; They breakdown dead bodies (dead organic matter) so as to ensure nutrient
circulation and availability of nutrients to producers (plants)
(Mention 001/2 mark, Role 001/2 mark) 01mark @point =03 Marks

(ii) FOOD WEB

Hawk (001/2 mark)

Snake (001/2 mark)

Toad Lizard

Worms Insects Field mice (001/2 mark)

Green plants (001/2 mark)

Food web=02marks

TOTAL=06 MARKS

9. a) A-Receptor (Sense organ)

B-Sensory neurone (Afferent neurone)
C- Relay neurone (intermediate neurone)/ (Inter relay neurone)
D- Motor Neurone (Efferent neurone)/ (effector neurone)
E- Biceps muscles
F-Tricep muscles (001/2 mark =03Marks)

b) (i) Function of part B

- It convey the nerve impulse from receptor (sense organ) to the central nervous system
(CNS) for interpretation of the touch stimulus (001/2 mark )

Function of part C
- It relay nerves impulse between sensory (afferent) neurone and motor neurone. (001/2
mark )
Function of part D
- It convey information from the central nervous system (CNS) to the effector organ (muscle)
to elicit an appropriate response (001/2 mark )

(ii) - Response shown by E-Biceps muscle contracts

- Response shown by F-Triceps muscle relaxes (011/2 mark )
TOTAL=06 marks
10. a) The man should first go and see a doctor for further checkup
(medical checkup) 01 Mark
b) Tuberculosis (TB) 01Mark
c) Tuberculosis is caused by bacteria called Mycobacterium tuberculosis
01 mark
d) Transmitted or spread by droplets when coughing or sneezing. 01 mark

Preventive measures
Patient should cover nose and mouth when coughing or sneezing in order to avoid spread of
mycobacterium Tuberculosis to the atmosphere. 01 mark

Medical treatment; attending hospital to know and get medicines / antibiotic such as Rifadin,
Rimactane and Myambutol which will cure the disease, normally the TB treatment is free so the
patient will obtain the medicines and medical diagnosis through government funds. 01 mark

TOTAL=06 marks

11. a) Excretion; Is the process whereby living organisms get rid of metabolic waste products
from their bodies. E.g Removal of urea from the body (02 marks)

b) Reasons for why plants lack excretory organs

i. Plants are non-motile (Limited movement) which result into higher reduced
metabolic activities hence less waste products are produced
ii. Some of the waste products are removed from the plants through leaf fall / abscission
iii. Some of the waste product s are used within the plants as a raw material. Example
oxygen from respiration during the night is used as raw materials in photosynthesis
iv. Presence of stomata aperture and lentcels in plants through which gaseous waste
products escapes-For Example Carbon dioxide which is the product from respiration
and oxygen is product of photosynthesis
v. Plants contain large vacuole for storage of waste products from metabolism such as
tannis and anthocyanins. Any 04 Points @1 marks =04 marks

TOTAL=06 Marks

12. a) Growth curvature

Is a process whereby the plant parts such as leaves, stems and roots show growth responses,
results in part of the plant growing away from or towards appropriate stimulus. 02marks

b) Types of joint and example

i. Pivot joint
Example; turning of head from side to side, found in neck and axis (cervical)

ii. Ball and socket joint

Example; Found in hip and shoulder
Rotation of limb in all planes

iii. Hinge joint

Example; Found in elbow and knee
- Swining of lower leg from side to side without moving your hip joint (one plane
only)

iv. Gliding joint

Found in spinal cord, the carpals of the palm and tarsals of the foot
Example allow the back bone, hands and feet to be flexible
Mention 001/2 mark, Example 001/2 mark=0 1mark
04 Points @01 marks =04marks
TOTAL=06 Marks
13. Corona Virus Disease of 2019 (COVID-19) Are the large group of viruses that are common
among animals or any family of corona viridae of the single stranded RNA viruses that have
lipid enveloped studded with club shaped projections infects birds and many mammals includes
human and snakes

In rare case they what scientists call Zoonotic, meaning they can have transmitted from animal
to human (01Mark)

Causative agent of the disease is; Corona virus or large group of viruses of the family Corona
viridae which infects birds and human being (01Mark)

Mode of transmission of the disease; Human Corona viruses most commonly spread from an
infected people/person to the others through;

The air by coughing and sneezing;

Through respiratory droplets produced; when an infected person coughs or sneezes and these
droplets produced can laid in the mouth or nose of the people who are nearby or possibly inhaled
into the lungs

Close personal contact such as touching or shaking hands; It is spreads from person to person
among those in contact/ in close contact it may be touching or shaking hands of infected person
which contain corona viruses and then touching their mouth, nose or eyes. This contamination
results to spread of disease

Touching an object or surface with the virus on it, then touching your mouth, nose or eyes
before washing your hands. Touching the object or surface that has corona viruses on it and then
by touching mouth, eyes or nose cause quick transmission of disease

Rarely facial contamination; When water become contaminated with facial materials
accidentally of human or other animals which have been affected with corona viruses and lead to
person to consume the contaminated water results to the spread of disease

Any 04 Points @ 011/2 marks

Mention 001/2 mark, Explanations 01 mark = 06 marks

Symptoms of the disease; for those with a weakened immune system, the elderly and the very
young, there is a chance the virus could cause a lower and much more serious respiratory track
illness like pneumonia or bronchitis. The following are the symptoms
Fever; The infected person shows an increase in temperature above the normal range due to
increase in the body’s temperature. The major increase in body’s temperature due to increase in
muscles contractions and causes of a feeling of a cold

Sore throat; The infected person has pain or irritation of the throat. It usually caused by
pharyngitis (inflammation of the throat) or tonsillitis (inflammation of the tonsils) this may result
from trauma

Felling of being unwell; general body weakness of the infected person is caused by the over use
of the muscles / group of muscles and also due to defects in biochemical metabolism that primary
affect muscles. The defect result to create low energy due to interfere with muscle ability to create
energy

Cough. Infected person undergoes voluntary or involuntary acts that clears the throat or breathing
passage of foreign particles, microbes, irritants, fluids and mucus. It is rapid expulsion of air from
the lungs. The symptoms are more frequent to the infected person
Headache; The infected person feel painful sensation in any part of the head, ranging from sharp
to dull, that will occur with other symptoms, sometimes occur due to lack of sleep

Runny nose; infected person shows excessive drainage, ranging from a clear fluid to thick mucus
from the nose and nasal passage in other circumstance occur due to cold exposure or hot
temperature
Any 04 Points @ 01 mark = 04 marks
Mention 00½ mark, Explanations 00 ½ mark

Prevention of the disease; there are currently no vaccines available to protect person against
human corona viruses infection. The transmission is reduced through

Washing your hands often with soap and water; washing hands often with soap and water for
at least 20 seconds. Regularly washing hands often with soap and water or use an alcohol base
hand sanitizer. This is the best way of avoiding getting sick and spread of illness. Washing of
hands based on palm to palm, between fingers, focus on thumbs, back of hands and focus on wrists
to remove corona virus.

Avoiding touching eyes, nose, or mouth with unwashed hands. If the hands are not clean or
sanitized and even not washed with soap and water after touching the contaminated objects or
surface. The best way is to wash or sanitize hands before touching eyes, nose, or mouth and also
wearing gloves in order to be free from corona virus contamination.

Avoid close contact with people who shows flu like symptoms: being away from such people
will reduce the chance of spread of disease and free from Corona virus contamination and the
maintaining personal hygiene.

Avoid hand shaking, hugging and kissing with any person especially those who came from
or with history of visiting affected countries/areas. So, by avoiding hand shaking, hugging and
kissing and keeping social distance enable person to be free from the disease

Cover your nose and mouth with tissue when cough and sneeze or cough and sneeze to your
flexed elbow. The use of tissue or elbow prevent spread of corona virus to the atmosphere or
surface or objects or nearby person.

Stay home and avoid travelling when you have flu-like symptoms. The infected or sick person
is advised to stay home from work, school and public areas in order to reduce possibility of being
in close contact or touching surface contain human corona virus

Any 04 Points @ 001/2 mark = 02marks

Clean and disinfect surface you often touch; cleaning of surface or object by using soap and
water to reduce the contamination and to reduce the ability of other people who are not affected to
be contaminated with human corona viruses. Sometimes use the sanitizer if are available to clean
the surface such as doorknobs, banister and electric switch.

Quarantine; The infected or sick person must be restricted in one place to prevent the spread of
disease and infected people also are under medical diagnosis.

Treatment; currently no vaccination and treatment of disease. 01 Mark

But scientists still work on Dexamethasone proves first life-saving drug.

Total = 15 Marks
14. Organic evolution; is the gradual development (changes) of organisms from simple life forms to more
complex life forms over a course of time.

The following are evidence of Organic evolution;

Fossil record (palaeontology).

- Palaeontology is the scientific study of fossils. Fossils are remains of organisms that lived in ancient
times. The remains were accidentally preserved in some naturally occurring materials like sedimentary
rocks. The fossils can be of footprints or traits and of skeletal parts. The fossils dated using Radioactive
isotope i.e. Carbon – 14(C-14). The age of fossil can also be estimated from the position in the rock
i.e. old fossils lay deep in the rock while those in the upper part are comparatively younger.
Cell biology and biochemistry.
- Genetic research revealed that basic similarities exist between cells from almost all kinds of living
things. Eukaryotic cells contain organelles in all cells i.e. ATP, DNA and RNA. The similarities show
that all cell types have a common ancestral origin.
Differences do exist between cells from different organisms. Organisms sharing the same chemical
characteristics are more closely related. This is known as biochemical homology.
Examples are;
- Most plants contain chlorophyll, cellulose and starch which is absent in animal.
- Vertebrates are the only animal that possess adrenaline and thyroxin.
- Only algae possess the orange pigment called fucoxanthin.

Comparative Embryology.
- At a certain stage of their development embryos of all vertebrates show resemblance e.g. they have tails
two chambered heart and gill slit. The relationship is thought to be the result of their common ancestry.

Comparative anatomy.
- Organisms with basic structural similarities have a common or related ancestry; those with much
difference have less evolutionary relation.
i) Homologous structures; similar origin but different functions. This is called divergent evolution, E.g.
• Forelimbs of vertebrates (pentadactyl = 5 digits) for flight (bat and birds), swimming (whale and
turtles), running (horse), holding things (man).
• Beak in birds; modified according to mode of feeding, length, shape and size.
• Feet structure in birds; modified to suit environment; claws-for flesh eaters, webbed-for filter
feeders.
ii) Analogous structures; different origin but similar functions. Brought about by adaptation of unrelated
species to similar environment. This is called ---Convergent evolution. E.g.
• Wings of bat/ birds and insect for flight.
• Eyes of human and octopus for seeing.

iii) Vestigial structures; In some animals certain organs (structures) have become greatly reduced or
functionless in the course of evolution, due to adaptation to different mode of life
e.g.
• Appendix in man, wings of flightless birds (kiwi, ostrich, and emu) tail in man (reduced coccyx),
hind limb in pythons and whale and muscle that move the ear in man, body hair in man

Comparative serology.
Serology is study of blood (serum) proteins. It has been found that animals that are closely related
evolutionary also have similar blood proteins. The results show that, human closed “blood relatives’ are
great apes i.e. chimpanzee, gorillas, monkey, tarsiers and lemurs.

Classification (Taxonomy).
Modern classification is based on the similarities and differences between the natural characteristics of
organisms. The organisms that share several characteristics are put (classified) under same group and are
believed to have arisen from common ancestor in the evolutionary history.

Artificial selection.
Man inbreeding experiments on useful animals, select individuals with desired traits and separate them
from others. After repeating this process for few generations, a new breed/high breed is formed e.g.
different breeds of cows, sheep, and dogs; plants like cabbage, cauliflower, and kohlrabi are said to come
from colewort.

Geographical distribution of organisms. (Geographical isolation).

Examination of distribution of living things on earth shows that regions with similar climates and
topography are not necessarily inhibited by similar species of organisms. However, the two regions are
inhibited by related but different species of animals. E.g. S. America has long tailed monkeys, illamas,
puma; Africa has elephants, gorillas, chimpanzees, camels, lions and antelopes. Australia has marsupials
like kangaroos, koalas, and bears

conclusion

Evidence from real life situation.

✓ Some bacteria have developed resistant gene to antibiotics.
✓ Some rats have the ability to withstand the toxic effect of poisons like warfarin.
✓ Possession of the sickle cell allele (Heterozygous individual) affords some protection
against the malarial parasite.
Introduction = 01 mark

Conclusion = 01 mark

Any 04 points @ 02 marks = 08 marks

Mention point = 01 mark , explanation = 01 mark

Total = 10 marks

15. a) Genetics is the study of heredity and variation 02marks

b). Let

R-be gene for Red fur

W- be gene for white fur 00½ mark

C- be gene for coat colour

In order to obtain F1 generation

Parental phenotype: Red cow X White bull 001/2 marks

Parental genotype: CRCR CWCW 001/2 marks

Meiosis 001/2 marks

Gamete 001/2 marks

C C C C
R R W W

Fertilization 001/2 marks

F1 generation CRCW CRCW CRCW CRCW 001/2 marks

All F1 are Roan, phenotypically TOTAL= 03 marks

F2 generation (selfing F1) by selecting two member and making cross

 Parental phenotype: Roan X Roan 001/2 marks

Parental phenotype: CRCw CRCW 001/2 marks

Meiosis 001/2 marks

Gamete 001/2 marks

C C C C
R W R W

Fertilization 001/2 marks

F2 generation, CRCR CRCW CRCW CWCW 001/2 marks

¼ Red cow ½ Roan ¼ White bull 001/2 mark

031/2 marks

i)Type of inheritance; CO-DOMINANCE. 01Mark

Total =10Marks
 ANSWERS
FORM FOUR EXAMINATION - SERIES 08

MARKING SCHEME
1.
i ii iii iv v vi vii viii ix x
B B D B E C E A B D

1Mark@=10TOTAL
MARKS

2.
i C

ii A

iii D

iv G

v A

1MARK@ =5TOTAL MARKS

SECTION B (60 MARKS)

3. a) i) Is a collection of different cells1Mark

ii) Animal tissues
-Blood
-Muscle
- Bone½ Mark 2 Points 1Mark

Plant tissues
- Meristematic
- Parenchyma
- Collenchyma
- Vascular
½ Mark 2 Points 1Mark
b) Is a process by which cells from the same origin become specialized for specific functions1 Mark
c) It leads to cell diversity which results in better performance of life processes 3Marks
07Total Marks
4. a) Is a type of nuclear division which produces two daughter cells with the same number of
chromosomes as the parent cell.1Marks
b) - Interphase
-Prophase
-Metaphase
-Anaphase
-Telophase½ Mark@2 ½ Total Marks
c) –For replacement of dead cells
- For increasing number of cells aid growth
- Some organism is able to regenerate part of their body
-For asexual reproduction
- It helps to maintaining genetically identical from one generation to another
½ Mark @ 2 ½ Total Marks
06 Total Marks
5. a) i) Helps people to understand themselves better
ii) The knowledge of biology enables people to conserve their surrounding environment which
is important to the welfare of mankind

iii)The knowledge of biology enables man to improve his standard of living and care for animals and
plants1Mark @ 2Points 2 Marks
b) i) Classification of bean plant up to class level
- Kingdom - Plantae
- Division -Angiospermatophyta
- Class - Dicotyledonous½ Mark @1½ Total marks

ii) Classification of toad up to class level

- Kingdom - Animalia
- Division -Chordata
- Class - Amphibia½ Mark @ 1½ Total marks
- Characteristics of dicotyledonous
i) They have tap root system
ii) They have leaves with net veins
iii)They have floral parts in four or five or multiples
iv) They produce seeds which contain two cotyledons
v)They have vascular bundles which form a ring in the stem½ Mark @ 1 ½ Total marks
-Characteristics of Amphibian
i) They have a skin which is always moist
ii) Their life cycle involves a larval form called a tadpole
iii)They have gills for gas exchange in the early stages of the development of the tadpole
iv)They have a heart which has three chambers½ Mark @ 1 ½ Total marks
08Total Marks
1. a) Is the system of assigning scientific names with two names, namely generic and specific1Mark
b) - It reflects evolutionary relationship
-For easy communication among biologists
-Short hand information1Mark @ 2 Points 2Total marks
c) Because viruses shows both living and non- living characteristics2Marks
06 Total Marks
7.a) i) Is sudden loss of consciousness arising from failure of blood to circulate properly to all
body parts particularly the brain1Mark
ii) - Emotion stress
-Low blood pressure
- Illness
- Injury which lead to loss of blood
-Bad news
- Dehydration½ Mark @ 4 Points 2Total marks
 b) –it save lives
- it prevent the worsen of injury and helps recovery
-it reduces pain
- it brings hope and encouragement
-it prevents further accidents ½ Marks @ 4 Points 2 Total Marks
06TotalMarks

8) a) i) Because it control other glands to produce hormone 1Marks

ii) Because during cold olfactory surface become dry which lead the receptor for smell fail to
detect smell during cold.2Marks
b) If the amount of glucose is in high amount in the blood, insulin convert the excess glucose to
glycogen and if the amount of glucose is low in the blood glucagon convert the stored
glycogen to glucose
Insulin
GLUCOSE GLYCOGEN3Marks
Glucagon06Total marks

9. a) i) - Have thin membrane to facilitate quick diffusion

- They are moisture for gases diffusion
- They have large surface are for maximum exchange of gases
- They are well supplied with blood capillaries for transportation of gases
- They are well ventilated to receives a steady flow of air ½Mark @ 4points 2marks

b) It helps the body to generate heat when body temperature is low especially during cold time
2½ Marks
c) When a ring of bark is removed from the tree it dies because phloem tissues are destroyed
hence translocation of food from the leaves to
parts below the ring is blocked.2½ Marks
07Total Marks

11. a) Because the food enters the oesophagus due to the series of wave-like muscular contractions of the
walls of the oesophagus start (peristalsis) and the food is pushed downwards towards the stomach and
other parts of the alimentary canal this means the movement of food in the oesophagus does not depend
on gravitational forces 3Marks
b) Mammals have different ways of reducing excess water from the body such as sweating, urination,
breathing, defecation. When a mammal’s body heats up the body regulates its temperature by sweating
hence the frequency urination is reduced 3Marks

12. i) A- Pelvic girdle

B- Ligaments
C- Articulate cartilage
D- Synovial fluids
E- Synovial membrane
F- Femur1Mark @ 6 Marks
ii) -Function of part B – Ligaments
- It is a tissue which connects bone to bone at the joint.1 Mark
- Function of part C – Articulate cartilage
- It minimizes friction happen when bones rub against each other.
- It helps the bone to enlarge because their cells are actively to divide mitotically.1
Mark

iii) Ball and Socket joint

- It is characterized by allowing movement in many directions including rotation
2 Mark
10Total Mark s

13.a) B – Represents dominant gene (black)½ Mark

b- Represents recessive gene (white)½ Mark
Parental phenotype s ½ Mark Black x White

Parental genotypes½ Mark BB bb

Meiosis ½ Mark

B B
Gametes½ Mark b b

Fertilization½ Mark

F1genotype½ Mark Bb Bb Bb Bb

Offspring of F1 generation: All black1 Marks

Genotypes of the parents are BB and bb1 Marks
Genotype of the offspring is Bb1 Mark

b)i) Is a tendency for certain inherited characteristics to occur in one sex than the other2Mark
ii) If coat colour in rabbit is a sex-linked trait, the possible phenotype and genotype are as follows
B – Represents dominant gene (black) ½ Mark
b- Represents recessive gene (white)½ Mark

Parental phenotypes ½ Mark Black x White

Parental genotypes½ Mark

X BY XbXb
Y
Meiosis½ Mark

Gametes½ Mark XB Y Xb Xb
Fertilization½ Mark

F1 genotype ½ Mark XBXb XBXb XbY XbY

Phenotypes: 2- Daughters are black

2- Sons are white1Mark

Genotypes are: XBXb and XbY1Mark

15Total Marks

14.INTRODUCTION
Minerals are organic compound containing elements which are essential for normal body
metabolism. These minerals are grouped into two macro and micro minerals.½Mark

MAIN BODY
Iron
Roles
- It is constituent of haemoglobin (red pigment)
1Mark
Sources
-Beans, liver, eggs, green vegetables
1Mark
Deficiency disorders
-Anaemia
1Mark

Calcium
Roles
-For blood clotting
-For proper functioning of the heart
-For proper functioning of nervous system
-For contraction of muscle
- Formation of bones and teeth1Mark
Sources
-Milk, cheese, eggs, fruits green vegetables, sardines
1Mark

Deficiency
-Weak bones and teeth which can lead to rickets and easily fractured bones
1Mark
Sodium
Roles
-For passage of impulse along nerve fibres
-Important in digestion 1Mark

Sources
-Table salt, sea water, meat, fish, poultry, eggs, milk
1Mark
Deficiency
-Poor passage of impulse along nerve fibres
- Nauseas exhaustion
- Muscle cramp1Mark
CONCLUSION ½ Mark
10 Total Marks

15. INTRODUCTION

Causative agent
-It is caused by flatworms called schistosoma haematobium or blood flukes. 2Mark

MAIN BODY
Transmission
-Adult flat worms live inside the blood vessels of an infected man’s urinary bladder. These
worms damage the walls of vessels (bladder) by the help of a sharp spine and get released through urine
and faeces. If an infected person egests or urinates in the bush the eggs find their way to the water bodies
through rain water. In water they absorb it and burst releasing embryo called miracidia.3Marks

Symptoms
-General body weakness and loss of weight
-Anaemia
- Loss of appetite
- Spleen became large
- Urine and faces mixed with blood pass out
At least four points ½ Mark @ 2Total marks

Preventives measures
-Destroy breeding places of snails by clearing vegetation along the canals ponds and rivers
- Introduce ducks into the water to eat snails
- Spray molluscides in stagnant water to kills snails
- Educate people to use toilets and boils the drinking water
At least four points ½ Mark @2Total marks
CONCLUSION 1Marks
10 Total Marks
 ANSWERS
FORM FOUR EXAMINATION - SERIES 09

MARKING SCHEME
1

Qn i ii iii iv V vi vii Viii ix x

Ans B B A B D E A A B C

1 Mark@ total 10 Marks

2

I II III IV V
G D M I A

1 mark @ = 05 marks.

3. (a) (i) Biology Laboratory-Is the special room or place where Biological experiments are
conducted.

(ii) Botany-Is the branch of Biology which deals with the study of plants 1mark@=2marks

(b) (i) Mirror-Reflect and Direct light to the observation under observation

(ii) Objective Lens-Magnifies the specimen under observation

(iii)Eye Piece-Has lens which magnify specimen either five times (x5) or ten times (x10) etc

(iv) Base-support the microscope

(v) Limb or Arm-Support the body tube, knobs, stages, diaphragm, and mirror also used for carrying
the whole microscope

(vi) Clip-Holds the slides contained specimen

(vii) Course Adjustment-Raise and lower the body tube in order to bring image into the focus

(viii) Stage-surface on which the specimen is placed. 0.5mark@=4marks

4. (a) (i) Water

• Carbonidioxide (0.5mark@=2Marks)
• Chlorophyll
• Sunlight
(ii) Glucose or carbohydrate any one point 1 mark

• Water
• Oxygen 0.5mark@=1Mark

(b) Adaptive features of ileum

i.It has finger like project called villi. It increase the surface area for the absorption of food

ii.Its very long has large surface area for the absorption of soluble product of digestion

iii.Have a large network of blood capilarites

Iv.That transport absorbed food to all parts of the body

v.Its folded

This increase surface area that is in contact with food (any 3 point 3 marks) each
point 0.5mark@=2.5Marks

5. (a) A zygote is a diploid nucleus formed by a fusion of the male and female gamete Whereas A sperm
is a male reproductive cell. it is a haploid cell. 1marks@=2marks

(b)(i) Oxytocin hormone

(ii) Prolactin hormone

(iii) Anti-diuretic (Vasopressin) hormone

(iv) Aldosterone hormone 1mark@=4Marks.

6. (a)epigeal germination-Is the kind of germination in which cotyledon brought above the soil surface.
While.-----(01)

Hypogeal germination-Is the kind of germination in which the cotyledon remains in the soil.----(01)

(b) condition necessary for seed germination

(i) Air (oxygen) (ii) water (iii) suitable temperature------(0.5mark@ total 1.5)

(c) -Germination is the process where a seed develops into seedling----(01marks)

• Seed absorb water through small hollow called micropyle and swell, then the food stored in the
cotyledon are then converted into energy by respiration of glucose for the development of
embryo, The seed split and plumule grow up wards while radicle grow down wards.-------
(01marks)
7. (a)(i) Genetics-Is the branch of biology which deals with the study of heredity and variations in
organisms.

(ii)Albinisms-Is the condition in which the body being unable to make melanin

(iii) Complete Dominance-Is the condition in which a dominant gene completely masks

the recessive gene.

(iv) Mutation-Is the sudden change of genetic materials .0.5 mark@=2Marks

(b)Let A-normal person

a-albino

Parental genotypes. Mr msakanjia be-Aa ,Mrs msakanjia be –Aa 4marks

8. (a) (i) Red blood cell-Used to transport oxygen gas in the body. (021marks)

(ii)White blood cell-Protect the body against infections. (01marks)

(b) Functions of Blood in Human being

(i) It transports nutrients from the ileum to the other parts of the body

(ii)It transports oxygen from the lungs up to other parts of the body

(iii) It distributes heat in the body

(iv) It transports hormone from endocrine glands to the site they are required

(v) It distributes white blood cells and antibodies in whole the body

(vi) Protect the body though the white body cells. any six point= 6marks

9. (a) Osmoregulation is the process of controlling the concentrations of mineral salts and

water content in the body (2marks)

(b) Mechanism of regulating sugar level in the blood

• The level of glucose in the blood is controlled pancreas which plays an important role in
maintaining constant level of glucose in the blood.
• The pancreas produces two hormones: which are glucagon and insulin. Those two hormones are
antagonistic that is they work together but in opposite directions to make sure that the level of
sugar stays near 90mg/100ml in human blood.
• If there is high level of sugar in the blood insulin convert an excess sugar into glycogen and if
there is low level of sugar in the blood, glucagon breakdown the stored glycogen into
glucose. (6marks)
10. (a) (i) Teas-can kill bacteria---(0.5mark)

(ii) sweat on the hand-Act as barrier to bacteria to enter in the body through the skin—(0.5mark)

(iii) on the bronchus-Exhalation process remove bacteria together with air----(0.5mark)

(iv) In the stomach-Hydrochloric acid produced by gastric gland destroy the bacteria---(0.5mark)

(b) (i) It is not health sleep in a closed room with many potted plants, because at night plants uses
oxygen for respiration process and because of that a person will compete for oxygen in the room with
potted plants. ---(02marks)

(ii) it is dangerous to sleep in a poorly ventilated room with a charcoal burner on because the
burning charcoal uses oxygen available and produce carbon monoxide. The carbon monoxide has high
affinity to haemoglobin than oxygen, then when carbon monoxide and oxygen combine the transported
of oxygen in the body will be prevented. The person will suffer from lack of enough oxygen in the
body,-----(02marks)

11. (a)Food chain is the flow of energy from the producer to consumers and food web is a network of
food chain 2marks.

4marks

12. 6marks

13

(a)i ) Special creation states that life began by a supernatural being, God. The being put life in matter
and living organisms formed. 2marks

(ii) Earth becomes extremely hot. Chemical reaction were initiated, this made simple elements to
combine forming simple molecules. As the earth cooled, complex organic molecules were formed. The
complex organic molecules formed sugars and amino acids.

More reactions resulted to formation of enzymes and replicating reactions leading to formation of
membranes surrounded by the enzymes and all other the complex organic compounds. This formed a cell
which is the basic unit of life. 3Marks.

(b) Lamack’s Theory states that changes are due to adaptations of organisms to their
environment,based on law of use and disuse. If organ is used more,it adapts more,if an organ is used less
it adapted characteristics are then inherited and passed on to the next offspring.

Is disputed because phenotypic changes cannot be transmitted to the offspring . Only genotypic changed
can.5marks.

(c ) Lamack’s Theory states that the changes are due to the environment. Darwin’s Theory states that
changes are due to changes in the genes and DNA.
In Lamack’s theory , the feature that survives is the one that is more used. In Darwin’s Theory, the
feature that survives is the one that adapts to the environment. The organism with adaptive features grow
to maturity and reproduce more offspring. 5 marks.

14 Well label diagram of ear (5 marks)

Mechanism of hearing

The pinna collect sound waves in the air, concentrates them and passes them through the external
auditory canal and to the ear drum. The ear drum moves back word and forward and those vibration start
up movements of the ear ossicles, which are passes on to the perilymph in the coiled cochlea. Nerve
ending in the sensory hairs of the cochlea. The vibration and impulses are send along the auditory never
to the brain. Where they are interpreted as sound. (10 marks)

15 Mechanism of gaseous exchange on alveolus with the aid of diagram

Actual gaseous exchange on of oxygen and carbon dioxide occurs in the alveolus

The alveoli are surrounded by the network of blood capillaries. When breathing in air with high
concentration of oxygen gas accumulates in the alveoli than in the blood stream; this causes oxygen gas
to diffuse out of the alveoli into the blood in the capillaries where if combine with hemoglobin to form
Oxyhaemoglobin complex which the transport oxygen gas to the tissue 01 mark

At the tissues the oxyhaemoglobin breaks and release oxygen and haemoglobin. The tissues uses
oxygen and release carbondioxide gas 01 mark

Production of CO2 (g) by the tissues causes the rise in the level of CO2 (g) in the tissues than in the
blood 01 mark

CO2 (g) then diffuses into the blood stream where it combine with haemoglobin to form carbomino
haemoglobin 01 mark

The capillaries transport CO2 (g) in this form to the alveoli.

The concentration of CO2(g) higher I the blood at this movement than in the air in the alveoli and hence
cause diffusion of CO2 (g) from the blood into the alveoli. CO2 (g) is then transported to the atmosphere
through bronchioles, glottis, pharynx and finally nostrils.

5marks

Diagram of alveolus showing O2(g) and Co2(g) exchanges (01 mark for heading 04 marks for the
sketch
 ANSWERS
FORM FOUR EXAMINATION - SERIES 10

MARKING SCHEME

I II III IV V VI VII VIII IX X

E C D B D A A B B B

@ 1 = 10 MARKS

2.

I II III IV V
H F E A C
@ 1 x 05 = 05 marks

3. (a) (i) Thrombocytes

- Necessary for blood clotting 01

- Prevent loss of blood

(ii) Plasma
- Transportation of dissolved food substance
- Transport hormones
- Distribute heat/regulate body temperature 01
- Transport waste products from the tissue to the execratory organs

(iii) Leukocytes
- Engulf foreign bodies
- Produce antibodies for defense against diseases 01

@ 01 x 03 = 03 marks
(b)
Red blood cell White blood cell
(i) Has haemoglobin Has no haemoglobin
(ii) Smaller in size Large in size
(iii) Lack nuclear Nucleated 03
Cancave in shape Have no definite shape
(iv)

4. (a) (i) Germination

Is the development of the seed into seedling

 (ii) Seed dormancy
Is the state of inactivity which prevent the seed from germinating even
under a favorable conditions./ Inability of the seed to germinate

(iii) Seed viability

Is the ability of the seed to germinate

@ 1 x 3 (03 marks)

(b) Factors that affect the rate of growth in plants. (Any three)

(i) Light: Adequate light is necessary for photosynthesis to take place so as to

manufacture food which is necessary for plant growth.

(ii) Temperature: Temperature affect the rate of metabolism hence growth any
temperature deviation may affect plants growth.

(iii) Water: Trowing plants contain as much as 90 percent water. Water also
play a crucial role for photosynthesis respiration and transportation.

(iv) Soil: Plant grow well where the foil contains proper humidity and the right
balance of all the mineral and nutrients.

(v) Carbondioxide and oxygen.

Oxygen: Is essential for respiration and utilization of by-products of
photosynthesis.

Carbon dioxide: Is required for manufacturing of sugar by plant and

finally contribute to the proper plants growth. Any 03 points @ 01 x
03 (03 marks)

5. (a) Digestion: Refers to the breaking down of food into simpler soluble form to be

absorbed and utilized by the body. 02 marks

(b) (i) Because woman show great need for iron minerals than men. Also unpolished
cereal are rich in minerals like selenium and manganese which are needed
by pregnant (expectant) mother to maintain good health and proper
growth of foetus.

(ii) Because pancrease secretes the digestive juice that contains digestive
enzymes but possess no room for digestion of food hence not considered
as site for digestion of food substrates.

@ 02 x 2 (04 marks)
6. (a) (i) Excretion: Is the removal of waste products of metabolism white
Regulation is the maintenance of constant internal body environments
and needs.
(b) (i) Bile – Liver 01
(ii) Sweat – Sweat gland 01

(c) When blood sugar level rise above the normal level beta cells of islet of Langerhans
in the pancrease release (secretes) insulin hormone;
Insulin hormone convert excess glucose into glycogen which is then stored in the
liver for future use. 02

7. (a)
Ball and socket joints Hinge joints
(i) They allow bones to be moved freely in (i) Allow restricted movement in one plane
all planes. only
(ii) Located the shoulder and hips (ii) Located at the knee and elbow
Any @ 1 ½ x 2 = (03 marks)
(b)

Skeletal muscles Cardiac muscles

(i) Attached to the bone (i) Found in the heart only
(ii) Controlled by somatic nervous system (ii) Controlled by at automatic/autonomic
nervous system
(iii) Aid movement of the body eg limbs (iii) Pumping of the blood
(iv) Fatiqued (iv ) Cannot undergo fatiqued
v) Voluntary vi) Involuntary

Any two @ 1 ½ x 2 (03 marks)

8. (i) Carbondioxide concentration in the blood: High amount of carbondioxide in the

blood lead to increase in rate of breathing.

(ii) Haemoglobin concentration: The increase in the rate of breathing triggers on if the
concentration of haemoglobin in the blood is low, led oxygen reaches the cell and
breathing rate increase to compensate the shortage to meet the oxygen demand.

(iii) Physical exercise: The rate of gaseous exchange increase during physical exercise
so as to provide the body cell with enough oxygen to aid muscle contraction and
relax white at rest state the rate of breathing reduced.

(iv) Atmospheric pressure: The higher you go (climbing mountain) the rate of
breathing increase due to increase in atmospheric pressure and decrease of amount
of oxygen. (v) Age and healthy status (Any three @ 03 x 2 = 06 Marks)
9. (a) (i) XhY
(ii) XhXh
(iii) XHY
(iv) XHXH

(v) XHXh @ 00 ½ x 5 ( 2 ½ marks)

9. (b) Let H be the gene for normal

Let h be the gene for haemophilia 00 ½

Parental genotype HhY x XHXh

Parental phenotype Haemophilic x carrier ½

Male Famale

Parental Genotype HhY XHXh ½

Meosis
Gametes
Fertilization Xh Y XH Xh ½

X HX h X hX h X hY X hY ½

Carrier female Haemophilic Normal

female Male ½

Haemophilic

Male

03marks

10. (a) Modula oblongata regulate the following – Heart beat, swallowing, sneezing,
shivering and other involuntary activities. Will not be regulated 02 marks
Hypothalamus

- Coordinate and control autonomic nervous system.

- Control thirsty, appetite and sleep. Will not be conceived 02 marks
Cerebellum

Fail to Maintain posture and balance. [02 marks]

11. (a) Cell differenciation
Refers to the specialization of the cells to the functions. 02marks

(b) (i) Root hair cell – Absorb water and mineral salts from the soil. 02marks

(ii) Guard cells – Control opening and closing of the stomata. 02 marks
(iii) Pollen grain cells – for pollination
(iv) Palisade cells- Photosynthesis

12. All living things share the following common characteristics

(i) Nutrition : Is the way organism obtain food form their environment.

(ii) Excretion: Is the removing out of waste products of metabolism.

(iii) Reproduction: Is the ability of a living things to give new ones of their own kind.

(iv) Respiration: Is step by step breaking down of food to release energy. Any
three 02 x 3 (06 marks)

13. (i) Manufacturing of antibiotics eg. Streptomycin manufactured by bacteria.

(ii) Recycling of the nutrients e.g. Nitrogen fixing bacteria.

(iii) Decomposition of organic matter.
(iv) Digestion of cellulose of Ruminant animals.
(v) Sewage system, bacteria break down pollutants.
(vi) Formation of cheese, butter and flavours of four milk.
(vii) Increase soil fertility

Intro – 02 marks) Any 6 points @ 2 x 6 = 12 marks Conclusion 01 mark

14. (i) Physical contacts with infected person e.g. HIV – Sexual contacts with infected
person (victim) without safety measures, - Covid-19.

(ii) Contact with contaminated surface on object.

(iii) Insects or animal bites capable of transmitting the disease (e.g. Malaria by female
anopheles mosquito, tick and tsetse fly bite.

(iv) Air bone such as tuberculosis and Covid-19.

Intro – 01 mark) Any 4 points @ 2 x 4 = 08 marks Conclusion 01 mark

= 10 Marks
15. (i) Anyone who has exposed to the risk behavior.

(ii) Anyone who is seriously considering changing of behavior.

(iii) Those who diagnosed with a sexual transmitted infection or tuberculosis.

(iv) Those who have had more than one sexual partners.

(v) Women or men whose spouses may be living with HIV (discordant couples).
 ANSWERS
FORM FOUR EXAMINATION - SERIES 11

MARKING SCHEME
1. Multiple choices

I II III IV V VI VII VIII IX X

A C D B B D E A C C

1 mark each = 10 marks

2. Matching items

LIST A
I II III IV V V

LIST B B D C A H F

1 mark each = 5marks

3. (a) (i) Biology is the branch of science which deals with the study of life (2 marks)
(ii) Zoology is the branch of biology dealing with the study of animals (2marks)

(b)Reasons for studying biology

• To appreciate nature
• To know our environment better
• To develop career like doctors, teachers, Nurse
• Encourage international cooperation
• To identify and group living organisms
• To acquire research skills
Any 4 points 1 mark each = 4 marks

4. (a)
(i) Trophic level is the group of living organisms with similar nutritional habits(1mark)
(ii) Food chain is the linear flow of energy from one living organism to anotherin a
community (1 mark)
(iii) Food web is the interconnected food chain (1 mark

(b)

(i) Predation is the feeding relationship in which one organism kills and eat other organisms e.g.
Lion kills and eat an antelope (1 mark)
(ii) Parasitism is the feeding relationship between organisms of differentspecies in
which one benefits while the other do not but get harmed. E.gHuman being
and malaria protozoa (1 mark)
(iii) Mutualism is the feeding relationship between organisms in which theyboth benefits
e.g. Rhizobium bacteria and legumes (1marks)
5. (a) Characteristics of insect pollinated flowers
• Large, heavy and rough pollen grains
• Small anthers with short filament
• Short, small and sticky stigma
• Large flowers, conspicuous with bright coloured petals
Any 4 points 1 mark each = 4
(b) Cross pollination is the transfer of pollen grains from the anther of a flower of one
plant to the stigma of a flower of another plant of the same specie. (0.5 mark)

(c) Agents of pollination

• Wind
• Water
• Animals like insects
(0.5 mark each) = 1.5 marks
6. (a)
(i) Human Immunodeficiency Virus
(ii) Sexually transmitted Infections
(iii) Sexually Transmitted Diseases
1mark each = 3 marks
(b)
(i) Lungs
(ii) Tracheoles
(iii) Lungs, Skin and Bucal cavity
1 mark each = 3 marks
7. (a)
(i) Lamarck’s theory
He proposed that organisms my develop a particular structure in responseto environment
demand. According to his theory of use and disuse he proposed that the more an organism use its part
the active it become and theless part is used the more weak it become such that may eventually
become rudimentary.
e.g. Long necked giraffes were result of stretching their neck upon competitionof food.
Flightless birds like Kiwi, emu, ostrich were a result of not using their wings. These acquired
characteristics can be passed into new generation resultinginto the formation of new species

(ii) Darwin’s theory

The theory explains natural selection of occurrence of variation among organisms of the same
species which occur by chance then passed through new generation. Also limiting factors or
eliminating factors exists in the environment such as food, space, disease, predation etc..

And for those organisms who struggle for existence will survive and their traits will be passedinto
new generation

Any 2 theories 1.5 marks = 3 marks

(b)
(i) Pseudopodia
(ii) Cilia
(iii) Fins
(iv) Limbs
(v) Setae
0.6 mark each = 3 marks

8. (a) Shock is lack of enough blood supply in the vital

organs (1 mark)Causes of Shock
• Emotional stress
• Low blood pressure
• Illness e.g. severe Malaria
• Severe injury
• Heart failure
Any 2 points 1 mark each = 2 marks

Causes of fainting

• Excessive physical exercise

• Severe injury

• Disease like epilepsy

• Improper ventilation
Any 3 points 1 mark each = 3 marks

9. (a) Role of:-

Water

- To soften the seed coat

- To activate enzymes in the seed

- To rapture the seed by increasing pressure in the seed

Air

- - For generation of energy during aerobic respiration required forthedevelopment of the

seedling

Temperature
- For activation of enzymes to function
1.5 marks each = 4.5 marks
 (b)

Epigeal germination Hypogeal germination

i. Cotyledons are forced above the Cotyledons remains below the ground

ground

ii. The hypocotyls elongates Epicotyls elongates

iii. Cotyledons photosynthesize Cotyledons do not photosynthesize

Any 3 points 0.5 mark each = 1.5 marks

10. (a) Reduce Reuse Recycle (1 mark each = 3marks)

(b) - Spread of diseases

- Production of unpleasant smell

- -Death of aquatic plants and animals

- Reduced agricultural products

Any 3 points 1 mark each = 3 marks

11. (a) Classification - is the grouping of organisms based on their similarities anddifferences

Taxonomy – Is a field of biology that deals with classifying organisms Or Is a scienceof

classification

1 mark @ = 2 marks
(b) (i)
-Natural system of classification
-Artificial system of classification
1 mark @ = 2 marks
ii.

Artificial classification Natural classification

• It deals with observable features • It deals with observable and non –observable features

• Requires simple skills • Requires advanced scientific skills

• Based on individuals interest • Based on international standards

• It is usually fast and inexpensive • Takes more time and it is costly

• Less accurate • More accurate

Any 2 diferrences 1 mark each= 2 marks

 12. (a) Genotype for F1 is: All are Ss
Genotype ratio of F2 is 1:2:1Phenotype ratio F2 is 3:1
1 mark @ = 3 marks
(i) Total number of wrinkled seed is 1831
(ii) Total number of smooth seed is 5493
1.5 mark @ = 3 marks

13. (i) Cholera (1 mark)

(ii)Vibrio cholera (1mark)
(iii)- Proper sewage disposal
• The use of clean and safe water
• Eating hot foods
• Personal hygiene
• Laws should be enacted to observe hygiene
• Washing hands with soap after toilet visit
Any 4 points 2 marks each = 8 marks

14. Risky behaviours

Are habits or conditions that can lead to poor health, illness or even death (2 marks)
e.g. Alcoholism, drug abuse, unprotected sexual intercourse (1 mark)Factors
• Access to drugs and alcohol
• Lack of social support
• Lack of self acceptance
• Wrong notion
• Peer pressure
• Fun
• Poverty
Any 6 points 2 marks each = 12 marks
15. (a) Rape is a situation whereby sexual intercourse is done under the
application offorce

(1 mark)
(b) Causes
• Drug abuse
• Wearing seductive clothes
• Local beliefs
• Peer pressure
Any 3 points 1 mark each = 3 marks
(c) Consequences
• Sterility
• Transmission of infection and diseases
• Psychological problems
• Unplanned pregnancies
• Death
Any 3 point 1 mark @ = 3 marks
(d) Ways to avoid rape
• Strong punishment for rapists eg 30 years in jail
• To educate people on effects and consequences of rape
• Wearing decent
• Girls should avoid walking alone across risk places
• Government to deal accordingly against drug abusers
Any 3 points 1 mark each = 3 marks
 ANSWERS
FORM FOUR EXAMINATION - SERIES 12

MARKING SCHEME

1.
QUESTION NO: i ii iii iv v vi vii viii ix x
ANSWER C D A B A C A C D D

2.
LIST A i ii iii iv v
LIST B F D E B C

SECTION B (60 marks)

3. a) First Aid is a vital thing (02marks @ ½ )
Reasons:
i) it saves life of a victim
ii) it bring hope to a victim
iii) it promote early recovery
iv) it reduce pain and suffering
v) it prevent victims condition to be more worse

b) Methods that can keep us free from Accident at home and school (02marks @ ½ )
i) Don’t walk barefoot outside
ii) Don’t touch electrical equipment with wet hands
iii) Use poisonous substances as directed on the labels
iv) Don’t allow children to play near water bodies
v) Store oxidant, flammable and explosive substances far from source of heat
vi) Don’t irritate dangerous animals example dogs and bees
c) First Aid: Is the immediate assistance given to a sick or injured person before getting
professional medical help.(1mark)
First Aid Kit: Is a box that contains items that are used to give help during an
emergence.(1mark) (Total 06 marks)

4. a) Difference between (03marks @ 01)

Prokaryotic cells Eukaryotic cells
i) They don’t have true nucleus - They have true nucleus
ii) Mostly are smaller in size then - They are bigger and more complex
eukaryotic cells than prokaryotic cells
iii) They lack membrane bound - They have membrane bound
organelles organelles
iv) Prokaryotes reproduce by binary - Eukaryotes reproduce by sexual or
fission asexual means
v) Example bacteria cell - Example plant and animal cells

b) Specialized animal cells with one function (03mark @ 01)

i) Red blood cell:- Used to transport oxygen and carbondioxide gas in the body
ii) Sperm cell:- Used for reproduction and it produced by male
iii) Ovum cell:- Is a female gamete used for reproduction
iv) White blood cells:- Used to fight against infections and diseases (Total
06marks)
 5. a) The other name of the following (1 ½ @ ½ )
i) red blood cells – ERYTHROCYTES
ii) White blood cells – LEUCOCYTES
iii) Platelets – THROMBOCYTES

b) (i) Diagram labeling (2 ½ @ ½ )

1. VENACANA 4. SEMILUNAR VALVES
2. RIGHT AURICLE 5. LEFT VENTRICLE
3. PULMONARY ARTERY

(ii) Adaptation of HEART

(i) It has muscular walls which contract and relax to pump blood
(ii) It has valves which ensure blood flows in only one direction and prevent
flow back of blood
(iii) It has septum which separate oxygenated blood from deoxygenated blood
(iv) It has aorta which transport oxygenated blood away from the heart to
other part of the body
(v) It has vena cava which enters deoxygenated blood from other part of the
body
(vi) It has pulmonary artery which transfer deoxygenated blood to the heart
for exchange of carbondioxide gas and oxygen gas
(vii) It has pulmonary vein which enters oxygenated blood from the lungs
(02@1/2marks) (Total 06marks)
6. a) (i) Gaseous exchange: Is the movement of oxygen and carbondioxide across a
respiratory surface
(01mark)
(ii) Respiration: Is the process by which food substances are broken down to provide
energy
(01mark)

b) Differences between Aerobic and Anaerobic respiration (02marks @ 01/2)

AEROBIC RESPIRATION ANAEROBIC RESPIRATION
i) Oxygen is used for breakdown the - Oxygen is not used to produce energy
food to produce energy - Small amount of energy are produced
ii) Large amounts of energy are product - Water is not produced
iii) Water molecules are produced - Food substances are not completely
iv) Food substances broken down broken down
completely - Takes place in the cytoplasm
v) Takes place in the mitochondria and - Lactic acid is the end product to
cell membrane animals and alcohol in plants
vi) Carbondioxide and water are the end
product

c) (i) In the nose there is hair like structure for traping dust and microorganisms
(ii) The nose is connected direct with gaseous exchange system
(iii) In the nose trachea there is mucus which trap dust and microorganis also
dissolves the gas (02marks @ 01) ( Total 06marks)

7.a )(i)Chlorophyll (ii)Haemoglobin (iii)Bile

(1mark@=3marks)
(b)Components of Health are:-1.Physical health 2. Mental health 3. Social
health(3@1mark)(Total 06 marks)

.
 8.(a) Reflex action:- Is a fast and automatic responses which they cannot be controlled
(01mark)
or
Is a rapid, automatic response to a stimulus

b) Differences between Nervous coordination and hormonal coordination (03marks ½ )

NERVOUS COORDINATION HORMONAL COORDINATION

i) Electrical signals are sent - Chemical substances (hormones)
through nervous impulses eroke a response
ii) The impulses are transmitted by - Hormones are transported by blood
Neurons - Effects are long lived or lasting
iii) Effects are short lived - Response is slow
iv) Response is fast - Always involuntary
v) May be voluntary or involuntary - May affect more than one target
vi) Usually specific organs

c) Major functions of mammalian skin (02marks @ ½)

i) It protect internal tissues example blood vessels and muscles
ii) Sensitivity to touch, pressure, pain and temperature
iii) Regulation of body temperature
iv) Excretion of waste product from metabolism example sweat (Total 06marks)
9.a)Ileum (1mark)
(b)(i)It secretes various enzymes for digesting food into their end products.
(ii)It is long and coiled for efficiency of absorption of nutrients.
(iii)It has finger like projection called VILLI which increases the surface area for absorption
of nutrients.
(iv) It has network supply of blood vessels for absorption and transport of nutrients into
cells and tissues.
(v)It has thin wall (Epithelium wall) that allows rapid diffusion of nutrients into blood
capillaries.
(vi)It has moist surface for easily diffusion of nutrients.
Any 5 points each 1mark =5 marks
(Total 06 marks)

10.[i]Organism X-Tapeworm or Taenia solium [1mark]

[ii] a-Hooks [0.5mark]
b-Suckers [0.5mark]
c-Head/Scolex [0.5mark]
d-Proglottides [0.5mark]
[iii]Alimentary canal vertebrates[0.5mark]
[iv] –Kingdom Animalia
-Phylum Platyhelminthes
-Class Cestoda[0.5mark@=1.5]
[v]Adaptations of animal x to its mode of life
-Has hooks for attachment in the alimentary canal
-Has suckers for absorption of food
-Has cuticle that prevent them from being digested by host enzymes
-Has segments called proglottides ,with both male and female sex organs [hermaphrodites] to
ensure their survival [2marks@1/2] (Total 07marks)
 11.Method for breaking seed dormancy
(i) SCARIFICATION - this method used to break down the hard testa of seed by
either knife, Razor blade or on stone and floor before a seed is planted on the soil.
This makes a seed to germinate by removing hard testa which it may delay to break
by using water in the soil. (21/2marks)
(ii) SOAKING – This is method where by a seed are placed in water for – over night or
two days in order to soften the seed testa, this makes seeds to germinate easily.
(21/2marks )
(iii) STRATIFICATION – This is the method in which seeds are placed (exposed) to
cold temperature or placed in refrigerator in older to break down the germinating
inhibitors. E.g. cytokine hormone.(point21/2 mark explanation ½=1)
(total 05 marks)
12 .let S-represent Smooth seeds[Dominant] and s-represent wrinkled seeds[1mark]
Parental phenotype Smooth seed *Wrinkled seeds
Parental genotype[2n] SS X ss
Meiosis

S S s s [1mark]

Fertilization

F1generation Ss Ss Ss Ss

Phenotype of f1 generation;All Smooth seed coat [1mark]

[b]F2-F1*F2]
Parental phenotype Smooth seed * Smooth seed
Parental genotype [2n] Ss Ss
Meiosis
Gametes S s S s
fertilization

[1mark]
F2 genotype SS Ss Ss ss
[i ] phenotypic ratio;1SS-Smooth
2Ss-Smooth
1ss-wrinkled
The ratio is 3;1 [1mark]
[ii]Total number of non pure breed Smooth=2/4*7324=3662[1mark]
[total 06 mark]
 SECTION C ( 25 MARKS)

13. Birth control is the process whereby parents decides to arrange and choose the time to
have children, to what intervals for each child, how many children to have in order to
provide good care for the children. (1 mark)

(a) The methods which suppress the motion and/or release of gametes are:
• Implants: these devices which are put in the uterus of woman and contains progesterone
hormone to suppress ovulation of eggs.
They can be for 2 to five years
(2marks).
• Contraceptive pills: are pills that contains hormones like estrogen and progesterone that
prevent ovulation process. they are taken orally and daily.
(2marks)
• Injectable: Are drugs that a woman is injected and they contains Oestrogen and
Progesteron hormone that suppress the ovulation
(2marks)
• Tubal ligation: This is the method of birth control in which the fallopian tube is cut and the
two ends are tied to prevent the passage of egg into fallopian. This suppresses the release
of egg.
(2marks)
• Vasectomy: This is the method of birth control in which the vas-deference of male are cut
and tied at each ends to prevent the passage of sperm from the epididymic to penis during
ejaculation.
This method prevent the release of sperm gametes in males.(2marks)
( Any 3 points 2marks each = 6 marks)
(b) The methods which prevent the union of gametes fertilization
• Condoms:Is a rubber that fits the penis and prevent the sperms to enter and reaching the
egg in female for fertilization. This method inhibits fertilization.
(2marks)
• Diaphragmor cervical cap. This is the rubber that is circular with spring around and fits
the cervices and vagina of female. This is rubber blocks the penetrations of sperms to
fallopian tube for fertilization.
(2marks)
• Spermicidal cream: This is the cream that put inside the women’s vaginal canal before
sexual intercourse, this cream kills the sperm passing forwards the egg inside the following
tube, and prevent successful fertilization.
(2marks)
• Rhythm method: This is the condition of abstaining from sexual intercourse during the
period of ovulation fertile days (danger days).
This prevents the successful fertilization of egg among partners and prevents pregnancy
occurrence.
(2 marks)
• Withdraw method: This refers to the removal of penis from vagina earlier before the time
of ejaculation. This method prevent fertilization ( 02Marks).
• Natural calendar: this methods show the menstruation cycle over 28 days per month.
This helps a woman to know the time of breed, ovulation and safe days. The partners are
able to control the number of their children. (2marks)
( any 3 point 2 marks each = 6 marks)
 ( C) The methods that prevents implantation of fertilized egg.
Intra- uterine devices (IUDS):these are small plastics or copper strips bent into loop or coil
that is placed in the uterus by qualified doctor or medical practioner and are left there for
estimate period of time. This prevents implantation process.
(2mark) (Total 15 marks)

14. Mammals detected changes in the internal temperature through hypothalamus. The
temperature receptors of the hypothalamus detect even the slightest change in temperature
then send impulse to effectors organs.(1 mark)
The physiological changes occurs when the temperature is high than normal in the body.
(hot conditions)are the following
• Sweating: during hot condition, the sweat pore opens more to release sweat. This contains
heat which is excess in the body and Enables to cool the body (1mark)
• Relaxation for hair erector Pilli muscles.
When the hair erector Pilli muscle relaxes, it causes the sweat pores to open and allows heat
to be lost from the body by sweating.
The hairs lie flat and heat lost convection and radiation.(1mark)
• Vasodilatation of superficial arterioles: during hot condition the blood vessels (arteries)
dilates and come beneath the skin surface to lose heat by evaporation and convection of the
flowing blood.(1mark)
• Decrease in metabolic rate: the metabolic rate of endotherms decreases during hot period
in order to reduce the production of heat in the body. this helps to reduce heat in the body
(1mark)
• Panting: The removal of heat from the body through mouth inform of water such as dogs.
This helps dog to cool its body during hot conditions.(1mark).
The physiological changes occur when temperature low than normal (cold condition)
Shivering: this is the involuntary rhythmic contraction of muscles which generate energy
in the body. This help to increase energy in the body.(1mark)
• Constriction of hair eractor Pilli muscles
During cold period the hair erector pilli muscles constrict and the hairs of the skin erect.
This causes the formation of GOOSE PIMPLES on the surface of the skin and it enables to
prevent heat loss by sweating(1mark)
• Vasoconstriction of superficial arterioles.
During cold condition, the blood vessels arteries)constricts and go deep from the skin
surface to prevent easily loose of heat by evaporation and convection of the following
blood(1mark)
• Increase metabolic rate:during cold coeditors the body’s metabolic rate increase in order to
increase the generation of heat in the body to replace the lost one.(1 mark) (total 10
marks)
15. Organics evolution: is a gradual change of organism into new species. Scientist believe that
all organisms arose from the common ancestor: The evidence which support organism
evolution.(2marks)

Evidence from comparative paleontology; this is the study of fossils. The palaentology shows
that the deeper fossils buried in the rock are the simplest fossils than the fossils of the upper
layer. This shows that organisms have changes overtime. (2marks)

• Evidence from comparative anatomy: anatomy is the study of internal structures of

organism in its habitant.
Examples Heart of Amphibian, Reptilia, Fish and mammals both have evolved from
the common ancestor.
Pentadactyl evolution: This show progressive evolution of bones of four limbs of
mammals. Both have five (5) digits but perform different functions.
Such as Fore limbs bat used for flying modified as wing
Fore limbs of whale modified. For swimming
Fore limbs of Human modified for grasping and holding as arm.
Fore limbs of horse modified for walking.
This suggests that Mammals evolved from common ancestor.
(2 marks)
• Evidence from comparative physiology: Physiology is the study of Basic body Function.
The various Physiological activities in various organisms are the same.
Example: PHOTOSYNTHESIS in plants is the same in all plants
RESPIRATION is the same in all organisms.
This suggesting that organisms evolved from same ancestor.(2marks)
• Evidence from Comparative Embryology: Embryology is the study of Embryology, the
very young human embryo Look Similar to very young embryo of other Mammals, Reptile,
Amphibians and Birds.
This shows that these organisms came from common (same) parent. The embryos both
have pharyngeal gills and tails.(2marks)
(Total 10 marks)