Name…………………………………………… Index No…………………/…….
School………………………………………… Candidates Signature……………
Date………………………………
231/1
BIOLOGY
Paper 1
(THEORY)
July 2011
TIME 2 HOURS
NAKURU DISTRICT SEC.SCHOOLS TRIAL EXAMINATIONS - 2011
Kenya Certificate of Secondary Education (K.C.S.E)
231/21
BIOLOGY
Paper 1
(THEORY)
July 2011
TIME: 2 HOURS
INSTRUCTIONS TO CANDIDATES
Write your name and Index Number in the spaces provided above.
Sign and write date of examination in the spaces provided above.
Answer ALL questions in the spaces provided.
FOR EXAMINERS USE ONLY
Questions Maximum Score Candidates Score
1-28 80
This paper consists of 8 printed pages
Candidates should check the question paper to ensure that all the
Papers are printed as indicated and no questions are missing
Download thousands of free kcse mock past papers @ http://www.kcse-online.info 1
1. Why are people with blood group AB universal recipients? (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
……………………………………………………………………………………………………….
2. State the organelles that would be abundant in (2mks)
(a) Palisade cell
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
……………………………………………………………………………………………………….
(b) Skeletal muscle cell
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
3. The diagram below represents a mammalian bone
(a) Name the bone (1mk)
…………………………………………………………………………………………………….
(b) State the part labelled X giving its function. (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..
(c) Name the type of joint formed by the bone at its anterior end with the adjacent bone (1mk)
……………………………………………………………………………………………………… ..
Download thousands of free kcse mock past papers @ http://www.kcse-online.info 2
4. Primary productivity in an aquatic ecosystem decreases with depth. Briefly explain this phenomena
2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
………………………………………………………………………………………………………….
5. State the adaptation of phloem which enables flow of substances. (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………..
6. Give two reasons why accumulation of lactic acid during vigorous activity leads to an increase in
heartbeat. (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
………………………………………………………………………………………………………….
7. State two functions of muscles found in the digestive system of mammals. (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
8. A student visiting a game park observed that an adult elephant flapping its ears twice as much as its
calf in order to cool its body when it is hot. Explain (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
9. The diagram below shows the position of an image formed in a defective eye.
(a) Name the defect………………………………………………………………………(1mk)
Download thousands of free kcse mock past papers @ http://www.kcse-online.info 3
Explain how the defect name in (a) above can be corrected (1mk)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
10. State the functions of the following organelles
(a) Centrioles (2mks)
………………………………………………………………………………………………………
………………………………………………………………………………………………………
(b) Rough endoplasmic reticulum (2mks)
………………………………………………………………………………………………………
………………………………………………………………………………………………………
11. Briefly explain why two species in an ecosystem cannot occupy the same ecological niche (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
12. Give two ways in which kingdom fungi is beneficial to man (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………. ………
13. State three advantages of metamorphosis to the life of insects (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
14. Give 3 reasons why plants do not experience a problem of excretion (3mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
………………………………………………………………………………………………………….
15. State the function of the following apparatus
(a) a pooter (1mk)
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..
(b) a pit fall trap (1mk).
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
Download thousands of free kcse mock past papers @ http://www.kcse-online.info 4
16. Give three reasons why water is necessary for germination (3mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..
17. Below is a diagram showing a pair of chromosomes A
(a) Name the process occurring at point A …………………...................................... (1mk)
(b) Give the biological significance of the process named in (a) above (1mk)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
(c) Name two structures in plants where the above process occurs (2mks)
…………………………………………………………………………………………………………
………………………………………………………………………………………………………
18. How is alveolus adapted to its function? (3mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
19. The diagram below illustrates the behaviour of blood cells placed in two different solutions
Solution X solution Y
Download thousands of free kcse mock past papers @ http://www.kcse-online.info 5
Process A Process B
(a) Suggest the nature of solution X and Y (2mks)
X……………………………………………………………………………………………………..
Y……………………………………………………………………………………………………..
(b) Name the processes represented by A and B (2mks)
A……………………………………………………………………………………………………
B…………………………………………………………………………………………………….
20. What is meant by the term sex-linked genes? (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
21. (a) State the event that occurs on the 14th day of a woman’s sexual cycle (1mk)
………………………………………………………………………………………………………..
(b) Name the hormone that triggers the occurrence of this event (1mk)
……………………………………………………………………………………………………….
22. State the structures of gaseous exchange in aquatic plants (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..
23. (a) What is meant by the term adaptive radiation? (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..
(b) Resistance to drugs by organisms is brought about by mutation. How is this achieved (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..
Download thousands of free kcse mock past papers @ http://www.kcse-online.info 6
24. (a) How do herbaceous plants achieve their support? (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
………………………………………………………………………………………………………
(b) State three importance of support in plants (3mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
25. The diagram below shows the behaviour of plants with regard to exposure to light
Light
rays light
rays
Before experiment After experiment
(a) State the type of response (1mk)
………………………………………………………………………………………………
………………………………………………………………………………………………..
(b) Explain how the named response in (a) above (3mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
……………………………………………………………………………………………………….
26. Study the food web below and answer the questions that follow
Download thousands of free kcse mock past papers @ http://www.kcse-online.info 7
Insectivorous birds
Hawks
Beetles Snakes
frogs
Aphids mice
slugs
Caterpillars Plants
From the foodweb
(i) Which organism would have the highest biomass?.......................................................(1mk)
(ii) what is the name given to the second trophic level?.....................................................(1mk)
(iii) Name a group of organisms not shown in the foodweb, but of great importance in the
ecosystem (1mk)
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..
27. (a) Name the two body parts of class arachnida (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
(b) Apart from number of body parts, state two distinguishing features between class arachnida and
class insecta. (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
………………………………………………………………………………………………………
Download thousands of free kcse mock past papers @ http://www.kcse-online.info 8
28. (a) Distinguish between Natural and acquired immunity (1mk)
…………………………………………………………………………………………………………
………………………………………………………………………………………………………….
(b)(i) Define the term Allergy (1mk)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
(ii) List two causes of allergy in humans (2mks)
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
Download thousands of free kcse mock past papers @ http://www.kcse-online.info 9