This document contains a biology exam paper with multiple choice and structured questions testing understanding of cellular structures and their functions, meiosis, human digestion, photosynthesis, energy flow in ecosystems, and cellular respiration. The paper covers topics including identifying plant and animal cells, labeling organelles, outlining stages of meiosis, explaining digestive processes, illustrating energy conversions in food webs, and comparing aerobic and anaerobic respiration. Students are required to demonstrate knowledge through labeling diagrams, describing processes, solving calculations, and explaining biological concepts and relationships.

1. SULIT 4551
Section A
[ 60 marks ]
Answer all questions in this section
For
Examiner’s
Use
1 Figure 1 shows a typical cell observed under the electron microscope.
FIGURE 1
(a) ( i ) Identify whether it is plant cell or an animal cell
…………………………………………………………………………………..
[1 mark]
( ii ) Give two reasons for your answer in (a)( i ) .
.…………………………………………………………………………..
………………………………………………………………………………
[2 marks]
(b) Name the organelles P, Q and R .
P : …………………………….………………………………………………..
Q : …………………………….………………………………………………..
R ; ……………………………..……………………………………………...
[2 marks]
(c) What is the significance of P for the cell ?.
………………………………………………………………………………..
[1 mark]
2
P
Q
R
S

2. SULIT 4551
(d) Explain the function of Q.
………………………………………………………………………………
………………………………………………………………………………
[2 marks]
(e) What would happen to the cell if organelle S is absent?
..……………………………………………………………………………….
..………………………………………………………………………………
……………………………………………………………………………….
[2marks]
(f) Explain one different between a root hair cell from the plant cell in
Figure 1
………………………………………………………………………………..
………………………………………………………………………………..
………………………………………………………………………………..
……………………………………………………………………………………
……………….
…………………………………………………………………………..
[2 marks] TOTAL
3

3. SULIT 4551
2 Diagram shows part of the stages of meiotic cell division in an animal cell.
The chromosome behaviour in stage S is not shown.
Meiosis
1
Meiosis
11
4
XStage P
Stage Q
Stage R

4. SULIT 4551
Diagram 2.1
(a) Name the structure labeled X.
…………………………………………………………………………………….
[1mark]
(b) (i) In Diagram 2.1, complete the diagram in stage S to show the
chromosome behaviour.
[1 mark]
5
Stage S
Stage T

5. SULIT 4551
(ii) State the chromosome activity in stage S.
…………………………………………………………………………………….
…………………………………………………………………………………….
[1 mark]
(c) Diagram 2.2 shows process Y which takes place in stage P
Diagram 2.2
(i) In Diagram 2.2, draw a diagram showing the appearance of the
chromosomes at the end of process Y.
[
1 mark]
(ii) Name the process Y.
6
Beginning of Process Y
End of Process Y

6. SULIT 4551
………………………………………………………………………………
[
1 mark]
(iii) State one importance of process Y to an organism.
……………………………………………………………………………………
……………………………………………………………………………………
[
1 mark]
(d) Diagram 2.3 shows skin cells. Cells L are cancerous cells which are
formed after normal cells are exposed to factor K.
Diagram 2.3
(i) Give two examples of factor K.
1. ……………………………………………………………………………
2 .……………………………………………………………………………
[2 marks]
(ii) Explain the formation of cells L.
……………………………………………………………………………………
……………………………………………………………………………………
…………………………………………………………………………………..
7
Cell L
Normal
cell

7. SULIT 4551
[2 marks]
(iii) State two ways to prevent the development of cells X.
1. …………………………………………………………………………
…………………………………………………………………………
2. …………………………………………………………………………
…………………………………………………………………………
[2marks]
3 Diagram 3.1 shows human digestive system.
DIAGRAM 3.1
Structure W in Diagram 3.1 involved in the digestion of sugar.
(a) (i) Name structure W.
…………………………………………………………………………
[1 mark]
(ii) Name the enzyme which digests sugar in W.
…………………………………………………………………………
[1 mark]
8
Duodenum
W

8. SULIT 4551
(b) (i) The action of enzyme named in a (ii) above follows a mechanism
“ Lock and Key” hypothesis.
Diagram 3.2 shows an incorrect steps of the mechanism.
+ +
DIAGRAM 3.2
Rearrange the steps of the enzyme action mechanism in a
correct order
……..……………………………………………………………………
[1 mark]
(ii) Name one product of the reaction in Diagram 3.2
……..……………………………………………………………………
[ 1 marks]
(c) (i) Explain how fat is digested in the duodenum.
……..……………………………………………………………………………
……..……………………………………………………………………………
……..……………………………………………………………………………
……..……………………………………………………………………………
[ 2 marks]
(ii) A student student eat too many oranges
Explain the effect of eating too many oranges on the digestion of fat in
the duodenum.
……..……………………………………………………………………………
……..……………………………………………………………………………
……..……………………………………………………………………………
9
steps :
Enzyme Product
Q
Sugar
1 II
P
III IV V

9. SULIT 4551
……..……………………………………………………………………………
[2 marks]
(d ) In a food preparation process, a housewife carries out the following
step:
Step 1: Marinate pieces of meat with strips of unripe papaya in a
basin.
Step 2: Immerse the basin in a container filled with water at 400
C for
30 minutes as shown in Diagarm 3.3
DIAGRAM 3.3
By using your knowledge in Biology, explain the steps taken by the
housewife.
….……………………………………………………………………………
…..……………………………………………………………………………
…..……………………………………………………………………………
…..……………………………………………………………………………
…...……………………………………………………………………………
…..……………………………………………………………………………
[ 4 marks]
10
Basin
water
unripe papaya
pieces of meat

10. SULIT 4551
4 Diagram 4.1 shows the release of gas from Elodea sp. through
photosynthesis.
Diagram 4.1
(a) (i) Name gas X.
.…………………………………………………………………………………
[1 mark]
(ii) What is the function of the sodium hydrogen carbonate solution?
…………………………………………………………………………………
[1 mark]
(b) (i) Explain briefly how gas X in (a) (i) is produced.
…………………………………………………………………………………
….………………………………………………………………………………
……………….…………………………………………………………………
………………..…………………………………………………………………
[3 marks]
11
0.1% Sodium hydrogen
carbonate solution
Light source
Gas X
Elodea sp.

11. SULIT 4551
( c) An Elodea sp. plant which was placed 10 cm from a light source
produced 20 oxygen bubbles per minute.
How many oxygen bubbles per minute would you expect to be released
if the lamp is placed at 5cm from Elodea sp.? Show your calculations.
[2 marks]
(d) An experiment was carried out to study the effect of temperature on the
rate of photosynthesis. The results are as shown in Table 4.2.
Temperature
(0
C)
Number of
bubbles
25 10
30 15
35 20
40 25
45 15
50 5
Table 4.2
Explain the above result.
…………………………………………………………………………………
….………………………………………………………………………………
……………….…………………………………………………………………
……………..…………………………………………………………………
…………………………………………………………………………………
[3 marks]
12

12. SULIT 4551
( e ) Diagram 5.2 shows a graph of the effect of light intensity on the rate
of photosynthesis.
Diagram 5.2
State how the rate of photosynthesis can be increased from curve P to
become curve Q
….…………………………………………………………………………………
….….………………………………………………………………………………
………………….…………………………………………………………………
[ 2 marks]
13
Rate of photosynthesis
light
intensity
Q
P

13. SULIT 4551
5. Diagram 5 illustrates the energy flow through a food web of a
terrestrial ecosystem
Diagram 5
(a) (i) Producers convert light energy from the sun and store it in their
tissues through a process. Name the process.
…………………………………………………………………………………
[1 mark]
(ii) Calculate the percentage of light energy from the sun that is
converted and stored in the producers’ tissues.
= ……………%
[2 marks]
(iii) State one reason why not all of the light energy from the sun is
14
Sun
Producer
6 x 104
k J
in plant tissue
Herbivor
5 x 103
k J
in animal tissue
Carnivore
30 k J
in plant tissue
Parasit
es
Organism P
3 x 108
k J m-2
year-1
to the ecosystem
Ion NO-
3
and NH+
4
in soil
Key:
Energy flow within the ecosystem
Energy flow out of the ecosystem
Energy in dead material

14. SULIT 4551
converted and stored in the producers’ tissues.
……………………………………………………………………………
[1 mark]
(b) (i) How much energy from the herbivores’ tissues is not being utilized in
the building of tissues in the carnivores?
= ………………kJ
[1 mark]
(ii) State what happens to the energy that is not utilized in the building of
tissues in the carnivores.
..………………………………………………………………………………
..………………………………………………………………………………
[1 mark]
(c) A pesticide is a chemical compound used to kill pests. The excessive
use of pesticides has almost killed all of organism P.
By using the information in Diagram 3, describe how this reduces the
production of protein in the producers.
………………………………………………………………………………
………………………………………………………………………………
………………………………………………………………………………
………………………………………………………………………………
[2 marks]
(d) (i) Name one example of a parasite in Diagram 3.
…………………………………………………………………………………
[1 mark]
(ii) When the parasites are eliminated from the ecosystem, the
producers, herbivores and carnivores are found to be healthier.
State your reason.
………………………………………………………………………………
..…………………………………………………………………………….
[1 mark]
( e ) By using the information in Diagram 3, construct a pyramid of
15

15. SULIT 4551
energy for that ecosystem.
[2 marks]
Section B
16

16. SULIT 4551
[ 40 marks ]
Answer any two questions from this section.
6 (a) Diagram 6.1 shows the structures of a unicellular organism which lives in a
freshwater pond.
Diagram 6.1
Explain the function of Z in osmoregulation.
[4 marks]
(b) Explain the similarities and differences between facilitated diffusion and active
transport in the movement of molecules across the cell membrane.
[8 marks]
(c) Diagram 6.2 and diagram 6.3 show two ways of preserving fish and vegetable.
Explain how the preservatives are effective in preservation of each type of the food.
[8 marks]
7 (a) Describe the similarities and differences between the structure of digestive and
17
Z
Diagram 6.2 Diagram 6.3
vinegar
Salt solution

17. SULIT 4551
digestion process of ruminant and rodents based on Diagram 7.1.
Diagram 7.1
[10 marks]
(b) Siti takes full cream milk, fried egg and roasted bread as her breakfast this
morning. Describe the digestion and absorption take place after that.
[10 marks]
8 (a) Diagram in Table 8.1 shows tissue M and cell N. M is found in a multicellular
organism and N is found in a unicellular organism.
Tissue M Cell N
Respiration equation
Glucose + Oxygen
Carbon dioxide + Water + Energy
Respiration equation
Glucose
Carbon dioxide + Ethanol + Energy
Table 8.1
Based on Diagram 8.1, explain the cellular respiration process that occurs in M
and N.
[4 marks]
(b) Diagram 8. 2 shows two individuals, X and Y, in two different situations. X is in a
vigorous activity while Y is at rest.
18

18. SULIT 4551
Diagram 8.2
Based on Diagram 8.2, explain the different in the physiological process that occurs in
organs R, S and T, for individual X and Y
[6 marks]
19
Individual X Individual Y
R
S
T

19. SULIT 4551
(c) Diagram 8.3 show a human circulatory system.
DIAGRAM 8.3
Based on Diagram 8.3, explain how the respiratory gases being transported in
human body.
[10 marks]
20

20. SULIT 4551
9 The size of the human population has been rising exponentially. People must obtain all
the basic need for their life. Human activities can affect the environment. We must protect
our ecosystem before it is too late.
Diagram 9
Diagram 9 shows the human activities.
a) Identify the human activities that can threaten /impact our ecosystem and suggest
measures to be taken to ensure a balanced of nature is maintained.
[10 marks ]
b) Discuss the effects of unplanned development and mismanagement to the well-
being of man and his ecosystem.
[10 marks]
END OF QUESTION PAPER
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