NAME:……………………….……..
STREAM…………………………………
SENIOR four
553/1
Biology PAPER 1
Exam 10
2 HOURS 30 MINUTES
Instructions to candidates:
- This paper consists of three questions.
- Answer all questions in sections A and B plus two questions from section C
- Section A circle the correct alternative, answers to section B in the spaces provided and
answers to section C in the answer booklets provided.
For Examiner’s use only
SECTION Marks Examiner’s signature
A
B No 31
No 32
No 33
C No
No
TOTAL
1
More exams? digitalteachers.co.ug Consultations? 0778 633 682
SECTION A: (30 MARKS)
Answer all questions in this section. Write the letter representing the most correct answer to each
question in the box provided.
1. Nitrogen compounds are continually being absorbed from the soil. Which one of the following
would enable the plant to receive a sufficient supply of nitrogen?
A: introducing denitrifying bacteria in the soil
B: adding ammonium sulphate to the soil
C: keeping the ground well watered
D: raising the same crop each year
2. Chlorophyll is removed from leaves before they are tested for starch because
A: otherwise the iodine would not react
B: boiling in water kills the leaf
C: this helps the alcohol to penetrate the leaf
D: colour changes would not be seen easily
3. In a certain food web, toads feed on insects while insects feed on green plants. At the same time,
hawks feed on green plants. At the same time, hawks feed on the toads. We can therefore
conclude that toads are
A: primary consumers B: primary producers
C: secondary consumers D: tertiary consumers
4. An individual was found to experience prolonged bleeding after having an injury. Which one of
the following vitamins is likely to be lacking in that individual?
A: vitamin D B: Vitamin B C: Vitamin K D: Vitamin B12
5. An experiment is set up as shown below
Semi permeable membrane
Water strong sugar solution
Which one of the following observations will be made after sometime?
A: water will be found to contain some sugar B: the level of water will increase
C: the level of sugar will decrease D: the sugar solution will become dilute
2
More exams? digitalteachers.co.ug Consultations? 0778 633 682
6. The offspring’s of a cross between short rooted radical and long rooted radical plants were found
to always be oval rooted. This is an example of
A: incomplete dominance B: mutation
C: complete dominance D: crossing over
7. In the human male, the tube used to carry both sperm and urine is the
A: ureter B: sperm duct C: somniferous tubule D: urethra
8. Which of the following bones is not part of the axial skeleton?
A: Ribs B: skull C: sternum D: scapula
9. If a cell has 46 chromosomes at the beginning of mitosis then at anaphase there would be a total
of
A: 92 chromosomes B: 23 chromosomes
C: 23 chromatids D: 46 chromosomes
10. A student looked through a microscope and found that it was dark. Which part of the microscope
would the student adjust to proceed with the use of the microscope?
A: fine adjustment B: Diaphragm
C: stage D: eye piece lens
11. The hormone that causes milk to flow from the mammary glands after birth is
A: lactogen B: Oestrogen C: prolactin D: oxytocin
12. Plants with bodies not well differentiated into roots, stems and leaves are grouped under the
A: pteridophytes B: spermatophytes
C: bryophytes D:gymnosperms
13. When water was powered in a sample of soil placed in a funnel in a laboratory, water quickly run
through and collected in a beaker placed under the funnel. This means that soil has;
A: high capillarity B: high water retention capacity
C: small air spaces D: low capillarity
14. Which of the following are not larvae?
A: caterpillar B: maggot C: chrysalis D: wriggler
15. Which of the following characterizes the blood in the renal vein?
A: high in CO2 and high in urea B: low in CO2 and low in urea
C: high in CO2 and low in urea D: low in CO2 and high in urea
3
More exams? digitalteachers.co.ug Consultations? 0778 633 682
16. The response by which tendrils curl around and cling to stems and other objects is an example of
A: thigmotropism B: photoperiodism
C: phototropism D: chemotropism
17. Which one of the organisms below has a growth curve represented by the graph below?
Body volume
Time
A: bacterium B: insect C: human being D: bony fish
18. In most living organisms, the respiratory gases enter and leave the body of the organisms through
the same passage except in
A: man B: fish C: insect D: flowering plants
19. When setting up an experiment to show that energy is released by germinating seeds, the seeds
are first soaked in sodium hypochlorite in order to
A: provide proper pH for germination
B: provide nutrients for germination
C: kill fungal spores that can release energy
D: absorb carbon dioxide that interferes with the experiment.
20. Gas exchange does not take place in
A: Alveoli B: Bronchioles C: Tracheoles D: Gill filaments
21. Joan accidentally stepped on a snake and was frightened. Which one of the following is least
likely to have happened immediately though it might happen later?
A: decreased heart beat B: constriction of skin blood capillaries
C: increased output of blood from ventricles D: increased breathing rate
4
More exams? digitalteachers.co.ug Consultations? 0778 633 682
22. The figure below shows the set up of an experiment to determine the region of most growth in the
plant root
A
The region of most rapid growth is marked
A B C D
23. Which of the following describes characteristics shown by vegetatively produced offspring of a
flowering plant?
A: wide variation in shape and type B: resistance to diseases
C: show early and rapid growth D: do not produce flowers
24. The following are results obtained from an experiment
Mass of dish = 50g
Mass of dish and dry soil = 200g
Mass of dish and soil after heating to red hot and cooled = 170g
Which one of the following represents the percentage of humus in the soil sample?
A: 15% B: 25% C: 75% D 20%
25. In the test for non-reducing sugars, sodium bicarbonate is used to
A: Act as an oxidizing agent B: Neutralize the excess acid
C: Act as a reducing agent D: Breakdown complex sugars into simple sugars
26. Which one of the blood groups will not agglutinate with any blood serum when mixed?
A: O B: A C:AB D: B
27. Birds that ride on the back of rhinos and eat bugs they spot in dung have a relationship with the
rhino that is best described as
A: symbiosis B: commensalism C: parasitism D: saprophytism
28. According to Darwin, evolution occurs
A: by chance B: because of natural selection
C: by adaptation D: rapidly
29. Which of the following sets of characteristics comprise of only characteristics of discontinuous
variation?
A: Tongue rolling, blood groups, sex B: height, body weight, intelligence
C: colour blindness, skin colour D: skin colour, height, albinism
5
More exams? digitalteachers.co.ug Consultations? 0778 633 682
30. To which one of the following bones is the biceps muscle attached by tendons?
A: scapula and radius B: humerus and radius
C: scapula and ulna D: humerus and ulna
SECTIION B: 40 MARKS)
Answer all questions in this section. Answers must be written in the spaces provided.
31. During the germination and growth of a cereal, the dry weight of the endosperm, the weight of the
embryo and the total dry weight were determined at two-day intervals. The results are as shown in
the table below
Time after planting Dry weight of Dry weight of Total dry weight
(days) endosperm (mg) embryo (mg) (mg)
0 43 2 45
2 40 2 42
4 33 7 40
6 20 16 37
8 10 -- 35
10 6 -- 39
(a) Complete the table above by filling in the weight of embryo on day 8 and day 10. (1 mark)
(b) On the same axes, plot a suitable graph to show the above information (11 ½ marks)
(c) What was the total dry weight on day 5? ( ½ mark)
(d) Explain the changes in dry weight of endosperm, weight of embryo and total dry weight with
time.
(i) Dry weight of endosperm (2 marks)
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
……………………………………………………………………………………………..
(ii) Weight of embryo (3 marks)
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
…………………………………………………………………………………………….
6
More exams? digitalteachers.co.ug Consultations? 0778 633 682
(iii) Total dry weight (3 marks)
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
……………………………………………………………………………………………..
32. A normal couple produced twins when one of the twins is an Albino.
(a) Explain why
(i) Parents with normal skin colour produced an Albino. (3 marks)
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
……………………………………………………………………………………………..
(ii) Only one of the twins from the same pregnancy was an Albino. (2 marks)
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
(b) Using suitable symbols, carry out a genetic cross to illustrate the difference in skin colour of
the twins (5 marks)
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
7
More exams? digitalteachers.co.ug Consultations? 0778 633 682
…………………………………………………………………………………………………
…………………………………………………………………………………………………
33. Three germinating beans with straight radicles were placed in a petri dish containing most cotton
wool as shown in (i) below. The dish was kept in a vertical position for 2 days in the dark. The
appearance of the beans after 2 days is shown in (ii) below.
(i) (ii) (iii)
(a) State the change that was observed in all the three radicles. (1 mark)
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
(b) Explain the observed change in (a) above (2 ½ marks)
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
8
More exams? digitalteachers.co.ug Consultations? 0778 633 682
(c) Petri dish (iii) was put in a clinostat which kept rotating. Explain the expected results after
two days. (2 marks)
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
(d) The seedling in petri dish (iii) had equally spaced marks in Indian ink along its length at the
beginning of the experiment. Draw a diagram to show the appearance of the marks after two
days. (1 ½ marks)
(e) Explain this appearance. (3 marks)
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
9
More exams? digitalteachers.co.ug Consultations? 0778 633 682
SECTION C: (30 MARKS)
Answer two questions from this section.
Answers are to be written in the answer booklets provided.
34. (a) Explain the mechanism involved and the pathway taken by oxygen from the atmosphere to
the liver cells in human beings. (8 marks)
(b) Describe how inspiration occurs in bony fish. (7 marks)
35. (a) What is parasitism? (1 mark)
(b) Give four effects of ecto-parasites on their hosts (4 marks)
(c) Describe how schistosoma mansoni is adapted to the parasitic mode of life (10 marks)
36. (a) Describe the process of fertilization in human beings. (5 marks)
(b) Explain how pregnancy is sustained until parturition. (10 marks)
37. Describe how the various parts of the human digestive system are adapted to their functions.
(15 marks)
END
10
More exams? digitalteachers.co.ug Consultations? 0778 633 682
