Now answer the following questions.

1. Euglena moves by the

A. whipping action of its flagellum
B. beating of its cilia.
C. rotating action of the flagella
D. pushing put a jet of water from an 6. What stage of mitotic division is represented in
organelle the diagram of the cell illustrated above?
E. beating the pseudopodia and cilia A Prophase
simultaneously. B. Telophase
C. Anaphase
2. In unicellular organisms, essential D. Metaphase
nutrients can be transported directly to E. Interphase.
all parts of their body by the
process of diffusion only because
unicellular organisms have 7. This stage of mitosis is characterized by the
A. a large surface area to volume ratio. A. movement of the chromosomes to the poles.
B. a large volume to surface area ratio B arrangement of chromosomes on the equatorial
C. permeable cell membrane plate.
D. outer membrane made of cellulose C. centromeres moving apart along the spindle.
E. their body always immersed in the D. interaction of the spindles with the chromosomes.
nutrient material. E. condensation of chromosomes and formation of
spindles.
3. Which of the following is not present in
the nucleus of a cell? 8. The .ability of organisms to maintain a constant
A. Chromosomes internal environment is known as
B. Nucleolus A. diuresis.
C. Mitochondrion B. endosmosis
D. Genes C. plasmolysis.
E. Chromatin. D. dialysis.
E. homeostasis.
4. The network of double membrane that 9 Double fertilization is said to occur in flowering
helps to convey materials through the plants because
cytoplasm is the A. two embryos are formed.
A. plasma membrane B. one egg is fertilized twice.
B. vacuolar membrane C. two sperms fertilize each egg.
C. nuclear membrane D. one embryo and an endosperm nucleus are
D. endoplasmic reticulum formed.
E. mitochondrion E. two sperms and two pollen grains are involved.

5. In aerobic respiration, oxidative 10. The bicuspid valve is located between the
phosphorylation takes place in the A. left auricle and left ventricle.
A. cytoplasm B. aorta and the left ventricle.
B. mitochondria C superior vena cava and the inferior vena cava.
C. lysosome D. right auricle and the superior vena cava.
D. vacuoles E. right auricle and the right ventricle.
E. ribosomes.
11 The pulmonary artery carries.
Study the diagram below and use it to A. deoxygenated blood from the right ventricle to the
answer Questions 6 and 7. lungs.
B. oxygenated blood from the right ventricle to the
lungs.
C. oxygenated blood from the left ventricle to the
right auricle.
D. deoxygenated blood from the left D if there is a shortage of water in the body the
ventricle to the right auricle. volume of urine produced decreases.
E. oxygenated blood from the lungs to the E. in the presence of antidiuretic hormone dilute
right auricle. urine is produced

12. Which of the following blood 17. The pigment in the malphigian layer responsible
components has the greatest affinity for for skin colouration is known as
oxygen and carbon- A. haemoglobin.
dioxide? B haemocyanin
A. Blood plasma C. chlorocruorin.
B. Leucocytes D. haemoerythrin.
C. Thrombocytes E. melanin,
D. Erythrocytes
E. Lymphocytes 18. Co-ordination is achieved in the body of
13. The thoracic cavity is separated from the mammals through the action of the
abdominal cavity by a sheet of muscle A. endocrine and nervous systems
called B. skeletal and nervous systems.
A. pleural membrane. C. muscular and nervous systems.
B. intercostal muscle. D circulatory and nervous systems.
C diaphragm. E. skeletal, muscular and nervous systems.
D. pericardium.
E. epiglottis. 19. Which of the following statements is correct of
hormones? Hormones are
14. Which of the following organs is A secreted into the blood through ducts.
responsible for controlling the body B secreted directly into the blood stream.
temperature regulation and water C. inactive chemical substances in the blood stream.
balance in mammals? D non-specific in their mode of action.
A. Kidney E, secreted at the site of the target organs.
B. Hypothalamus
C. Parathyroid 20. The pituitary is called 'master gland' because
D. Adrenal A it is located in the brain.
E. Thymus. B. its secretions are more numerous than those of
15. Deamination is the process during which any other gland,
A. excess amino acid is broken down into C its secretion controls other glands.
ammonia and a keto-acid. D. it is the only organ that produces hormone.
B. fats and oils are converted into an E. If regulates muscular movements.
emulsion for absorption.
C. excess glucose is converted and stored as 21 Auxins are produced in the
glycogen in the liver. A. petiole of leaver
D. glycogen is reconverted into glucose B. parenchyma of roots and shoots.
through the action of glucagon. C. epidermis of roots and shoots
E. excess amino acid is converted into D. apical regions of roots and shoots.
proteins. E. sclerenchyma tissues of roots
22. The brain and the spinal cord make up the
16. Which of the following statements on A. peripheral nervous system.
urine production in not correct? B. autonomic nervous system.
A. Concentrated urine is produced under C. central nervous system.
the control of antidiuretic hormone. D. somatic nervous system
B. The total volume of urine produced E. sympathetic nervous system.
depends on the need for water excretion.
C. If there is an excess intake of water, 23. Which of the following specialized structures
dilute urine is excreted. are stimulated by touch, pressure, pain, heat
and cold?
A. Receptors B phosphorus.
B. Synapse C. iron.
C. Cell bodies D. zinc
D. Myelin sheath E copper.
E. Relay neurones. 30. The relationship between a herbivore and the
bacteria which live in its caecum is known as
24. Which of the following is not correct A. parasitism.
about a fruit? It B symbiosis
A. may contain many seeds. C. commensalism.
B. is a mature ovary. D. saprophytism.
C. is covered by the pericarp. E. predation.
D. may develop from the receptacle 31. Autotropic nutrition may be defined in terms
E. possesses only one Score of food obtained
A. from other organisms in exchange for some
25. Which structure in the maize grain products
stores food? B. by the breakdown of complex substances.
A Radicle C. By an organism utilizing its own store of
B. Embryo energy.
C. Cytoplasm D. by synthesizing simple substances using
D. Seed coat energy from an external source
E Endosperm. E. in a synthesized form from other living
organism.
26. Which of the fallowing does not
occur during photosynthesis? 32. Which of the following is not classified as a
A. Energy from sunlight is absorbed terrestrial habitat?
B. Carbondioxide is evolved. A. Forest
C. Glucose is synthesized B. Guinea Savannah
D. Oxygen is given off C. Afro Alpine
E. water is split D. Littoral zone
E. Desert.
27 Even though some flowering plants 33. Which of the following does not contribute to
contain accessory pigments which the biomass in an ecosystem?
give them colours they still contain the A. Producers
pigment B. Food chains
A melanin. C. Consumers
B. chlorophyll D. Micro-organisms
C. xanthophyll. E. Saprophytes.
D carotene 34. Which of the following is not a characteristic
E chlorocruorin. feature of tropical rainforest habitats?
A. Trees with longer boles than those in
28 Which of the following is not savanna.
regarded as a micro-nutrient or trace B. Fewer canopy strata than the savanna
element essential for plant growth? C. Many more trees and climbers than
A. Phosphorus savanna
B. Zinc D. Plenty of leaf litter on the ground
C. Boron E. More diverse communities than the savanna.
D Silicon
E. Molybdenum, 35 Which of the following factors is not
29. In a water culture experiment a plant associated with aquatic habitat?
showed poor growth and yellowing of A. Temperature
the leaves. These symptoms were B Light intensity
probably due to the absence of C. Humidity
A. calcium. D. Turbidity
E. Wave action. A Use of nets with all sizes of mesh
B. Use of nets with a particular mesh size
36. Terrestrial organisms which are C. Ban on harvesting of some species
capable of maintaining their body D. Regulating the size of ships allowed into
temperatures constant within fairly fishing grounds
close limits are referred to as E. Limiting the period of fishing in the waters.
A. thermoclines B. homotherms.
C. poikilotherms D eurytherms. 43. Which of the following is not part of the
E stenotherms. objectives of conservation of natural resources?
37 Which of the following statements is A. To eliminate wild animals in order to
not true of a climax vegetation? It enable other plants and animals survive
A. is an ecological phenomenon. B. To use our resources on sustained yield
B. is a stable community. basis.
C. eliminates competition. C. To guard against indiscriminate killing of
D. results from succession. plants and animals.
E involves the colonization of a habitat. D To guard against the extinction and
exhaustion of natural resources.
38. The causative organism of sleeping E. To protect the environment
sickness is the
A. Trypanosome. 44 During blood transfusion, agglutination may
B. Plasmodium. occur as a result of the reaction between
C. Vibrio bacterium. A similar antigens and antibodies
D peniciltim. B contrasting antigens and antibodies.
E tsetse f|y. C. two different antigens.
D. two different antibodies.
39. Which of the following are not E. white blood cells from the two individuals.
causative organisms of plant diseases? 45. Which of the following major ideas were
A. Fungi proved by Gregor Mendel?
B. Viruses A, There is a tendency among organisms to
C. Bacteria increase rapidly in number if conditions are
D Nematodes favourable.
E. Cercariae. B. There is a struggle for existence among a
very large number of offspring.
40. The vector of the malarial parasite C. Nature selects organisms which will survive to
is the produce their kind.
A. male Anopheles. D. ACT species exhibit structural and
B female Culex. functional variations.
C male Cuiex E Characteristics of an organism are controlled
D. female Anopheles by genes occurring in pairs.
E female Aedes.
46. Assuming that VV is gene for normal skin
41. A constituent of the exhaust gases of and it is dominant, while 'a' is gene for albinism
motor vehicles which causes serious and it is recessive, what is the likely genotype
air pollution is of a couple which had 50% normal and 50%
A water vapour. B. carbondioxide. albinos?
C. carbon monoxide D. oxgyen. A AA. Aa
E. ozone. B. AA. aa
C. Aa. Aa
42. Which of the following steps would D. Aa aa.
not be taken to protect or conserve E. AA. AA
fishing grounds from over-
exploitation?
47. Which of the following is not a 52. Increasing specialization of structure and function
constituent of DNA? among animals of the same class or order for
A. Purine survival in new and different environments is
B. Phosphate called
C. Cystocine A. adaptive radiation
D. Deoxynbose B phylogeny
E Uracil C homology
D analogy.
48. Which of the following best describes E. ontogeny.
the homologous chromosomes? They
are 53. When large numbers of organisms share limited
A. a product of the division of a space and resources the result is
chromosome A immigration
B two identical chromosomes from each B commensalism
parent C symbiosis
C chromosomes arranged on spindle fibres D. extinction.
during cell division E. competition.
D daughter chromatides formed during
meiotic division 54. The change in colour of the chameleon serves as a
E chromosomes during telophase of mitotic means of
division. A. attraction to the opposite sex
B repulsion of the enemy
49. The haploid number of chromosomes in C. a camouflage from a predator.
man is D. regulation of body temperature
A 48. E. production of a variety of skin pigments.
B. 46.
C. 42. 55. Species can be defined as the group of organisms
D. 24 that
E 23 A. resemble each other and live m the same habitat
B are of common origin and are always found
50. If a cross is made between a pure- together
breeding red flowered plant and a pure- C. resemble each other and can interbreed freely.
breeding white flowered plant where R is D. resemble each other and occupy the same niche
dominant for red flower and r is recessive E are of common origin but cannot interbreed freely
for white, the most likely result of F.
generation will be 56. Which of the following is not an evidence of
A 75% red flowers and 25% white flowers. evolution?
B. all red flowers A. Fossil
C 75% white Flowers and 25% red flowers B. Anatomy
D. 50% red flowers and 50% white flowers. C. Embryology
E. all white flowers. D Genetics
E. Behaviour.
51. A man with blood group A (TAP) married
a woman with blood group O (pp). Which 57. Which of the following is not true about gene
of the following is the probable ratio of mutation? it
the blood groups of the offspring? A. introduces new traits into a population
A 1:1 B causes changes in the DMA.
B. 3:1 C may have unnoticeable effect on the phenotype
C. 2:1.1 D. always affects the chromosome number.
D 1.2:1 E. is a source of new genes
E 4:1
 E I, II, III and V.

59 The rate of transpiration will be highest in

A. I.
Study the diagrams below carefully. Use them B. II
to answer Questions 58 and 59 C. III.
D. IV.
E. V.

60. Which of the following has the most primitive

respiratory system?
A. Rat
B. Fish
C. Toad
D Grasshopper
E Lizard

58. The plants best adapted for life in the

desert are
A I and IV only
B. II and IV only
C III and IV only
D IV and V only

OBJECTIVE ANSWERS
1. A 2. A 3 . C 4 . D 5. B 6. A 7. E 8. E 9. D 10. A 11. A 12. D 13. C 14. B 15. A
16. A 17. E 18. A 19. B 20. C 21. D 22. C 23. A 24. C 25. E 26. B 27. B 28.. A 29. C
30. B 31. D 32. D 33. B 34. B 35. C 36. B 37. C 38. A 39. E 40. D 41. C
42. A 43. A 44. B 45. E 46. D 47. E 48. B 49. E 50. B 51. A 52. B 53. E 54. C
55. C 56. E 57. D 58. E 59. D 60. B

BIOLOGY ESSAY QUESTION

1 (a) List five morphological features that are characteristic of plants found in each of the following
habitats

(i) tropical rainforest,

(ii) savanna. In each case, state function of the features listed in

(a) to the plant,
(b) Explain the term: ecological succession,
(c) By means of a diagram only, outline the carbon cycle to show the relative importance of the cycle to life
in general.

2 (a) Describe an experiment to demonstrate the influence of auxins on the growth of plant shoot.
(b) List three uses of auxins in agriculture,
(c) Describe briefly the mechanism of transmission of impulses through a nerve fibre.

3 (a) Describe how the floral parts pf a named flower are adapted to wind-pollination,
(b) Explain how each of the following behaviours in animals affects the reproduction process,
(i) territoriafity
(ii) display,
(iii) seasonal migration.

4 (a) List three functions of the kidney,

(b) Make a labelled diagram of the mammalian kidney tubule nephron)
(c) Describe how the kidney carries out two of the functions listed in (a).

THEORY ANSWERS
1 (a) Five morphological features that are characteristic of plants are:
(i) For Tropical Rainforest: - tall trees with unbranched trunks, umbrella canopies - their barks are usually
thin - possession of buttresses - the leaves at bud stages have no protective coverings - the mature leaves
are oval in shape, have entire margins and possess drip – tip.
Functions of the features already listed: - Tall unbranched trunks - This is as a result of the plant
trying to get adequate sunlight; exposes the leaves for photosynthesis. - Thin bark makes it easier to lose
water through transpiration. Also possesses more of wood for timber. - possession of drip tip type of
leaves - for easy transpiration as well as to facilitate draining off of water. - Buttress - renders a lot of
support against powerful wind - bud leaves without protection - gives room for easy breakage of buds,

(ii) Savanna : - the roots are long and twisted - possession of thick barks - the trunks are gnarled (covered
with hard lumps) and twisted - possesses underground stems.
Functions of the features already listed: Long and twisted roots - facilitates absorption of water and
mineral salts, as well as help in fast recovery after fire. - possession of thick barks- gives them the ability to
tolerate harsh conditions such as fire. - Twisted and gnarted trunks - resist fire as well as -reduce
excessive transpiration. - Perennial grasses that gnartea tuffs - the inner part is protected by the outer tuffs
against fire. - Underground stems- make room for the plant to survive after a fire outbreak as well as
during dry season,

(b) succession: Is the progressive natural development of vegetation towards a climax, during which one
community is gradually replaced by others. It can be primary or secondary. Primary succession: Starts
on sites (e.g sand dunes, lava flows) which have not previously borne vegetation. Secondary succession:
Is one which follows the destruction of the original vegetation of an area The one time baren habitat is
eventually occupied by a community. This is termed ecological succession.
 EXPERIMENT TO DEMONSTRATE THE INFLUENCE OF AUXIN
2 (a) Aim: To demonstrate the influence of auxins on plant's growth
Apparatus: The young seedlings, jelly strip (soluble) and mica strip
Method: The two young seedlings were inserted at their tips (coleoptiles), one with the soluble
Jelly strip the other with the insoluble mica strip (control experiment) and were allowed for a reasonable
number of days (say 7 days).
Observation: The seeding with the soluble jelly strip was able to grow, while the one with insoluble mica
strip did not grow.
Conclusion: it stands to reason that the insoluble mica stripe did not allow the movement of the
growth hormones (i e auxin) downwards: hence no growth the soluble jelly strip allowed the diffusion of
the auxin and as such was able to grow.
(b) The three uses of auxin; (i) auxine spray prevents leaf fall (ii) auxin causes (he root cells to get
bigger (m) auxin regulates plants' growth from seed to fruits

MECHANISM OF TRANSMISSION OF IMPULSE

(c) Mechanism of transmission of impulse: It involves three phases viz:
(a) The resting potential
(b) The action potential and
(c) Repolarisation

(a) The resting potential: the cell surface membrane (i e neurolemma) is positively charged with respect
to the inside This is due to the accumulation of Na' outside and K+ within. This is brought about by
active pumping out of one ion and pumping in of the other (b) The action potential (the passage of
 impulse): The nerve impulses due to temporary change in the permeability of the neurolemma such that
it becomes permeable to Na+ and K' The Na+ thus rapidly enters the nerve by diffusion while the K +
diffuses in by opposite direction This in turn causes a change in the potential the outside becomes
temporarily negative in respect of the inside, (c) This is the reestablishment of the original resting
potential The Na+ is pumped out and the K+ pumped in.

(a) Description of how a named flower is adapted to wind-pollination: The name of the flower is
Maize (Zea mays). The following characteristics make it to be suited for wind pollination : (i)
The flowers produce a large number of pollen grains that are tight, smooth and powdery (ii) The
flowers are borne in large inflorescence and are produced in large numbers (iii) The stigmas are
large, feathery and hang outside the flower (iv) The flower possesses a dull colour (v) There is absence
of nectar, scent and perianth (not m all cases) (b) (i) Territoriality refers to the ability of various species of
animals to display a well developed social hierarchy in which the most powerful or the most senior or the
largest in number occupies a dominant position - The weaker males may not be able to mate and as
such the population will be checked, -the offsprings within a given territory are able to have enough to
eat - Controlled matings can result to the animals going into extinction. - It increases the chance of
having or finding mates, (ii) Display -involves all kinds of movements ranging from flashing of
colours, dancing, strutting tail feathers as in cock and peacock. Other example is gulls (colonial
seabirds with webbed feet and powerful flight), which feed the female during courtship and keep to
the same mate the rest of its life The opposite sex uses these approaches as a preamble for
copulation or mating (iii) Seasonal migration: it is the movement of animals carried out regularly,
often between breeding places and winter feeding grounds
Its influence on reproduction are as follows: - Fishes like salmon from sea migrate into fresh
water for breeding This is called anadromy - some fishes like fresh water eel migrate from the rivers
down to the sea for egg laying (spawning). This is referred to as catadromy - the coming together of
animals like birds during migration, gives room for mating of different species This produces
hybrids of good characters. - population of animals can be controlled by migration due to hazards
associated with it - migration starves predators from devouring then preys which in turn reproduce
rapidly when they must have come back not meeting their predators.
(a) The three functions of the kidney are:
(i) Excretion of uring (ii) Osmo-regulaiion and (iii) Elimination of toxins drugs and harmful
substances. Other functions are –production of heat - formation of urine - homeostasis -
regulation of water level – ma intenance of constant blood pH

(c) (i) Excretion of urine: The nephron is the unit of excretion The renal artery carries waste products
to the kidney Ultraftltration of the waste products take place in the glomerulus inside the Bowman's
capsule The filtrate moves down the kidney tubules In the loop shaded region of the tubule more
salts are added to the fluid, while water is removed from it. The resulting fluid is urine The urine is
then moved to the bladder by peristalsis, where it is stored until it is got rid of (ii) Osmo-regulation -
Water is constantly lost from the body through urine and other means This is regained by drinking and
eating moist foods If too much water is lost, or if excess salts are consumed the osmotic pressure of
the blood rises. This is detected by sensitive cells (Osmoseceptors) in the hypothalamus of the brain
These cause the posterior lobe of the pituitary gland to release antidiuretic hormone (ADH) into the
circulation The effect is the collecting duct to water, so that more water is reabsorbed by the kidney
and the urine becomes more concentrated The release of ADH therefore reduces the loss of water in
the urine and helps to maintain the osmotic pressure of the blood.