SECTION A MCQ

1

A

21

D

2

C

22

B

3

D

23

C

4

C

24

A

5

B

25

D

6

C

26

B

7

B

27

D

8

A

28

D

9

A

29

B

10

B

30

A

11

B

31

B

12

C

32

A

13

B

33

A

14

A

34

C

15

B

35

B

16

C

36

D

17

A

37

D

18

B

38

C

19

B

39

C

20

C

40

D

Section B
B
1a



(i) Carbon dioxide + water à glucose + oxygen
(ii) Water à oxygen + hydrogen
(iii)Magnesium + oxygen à magnesium oxide

Each correct [1]


b
Chemical changes are both harmful as well as useful [1]
Harmful – rusting of metals, decomposition of food [1]
Useful – photography [1] any two point [2]


c
Crude oil [1]
Distilled and mixed with other chemicals [1]
Used to make plastics, petrol, paint [1] any 2 point [2]




d

ii


iii
One sodiunn
One oxygen
One hydrogen


iv

1 copper atom
1 sulphur atom
4 oxygen atoms




Number of atom /size correctly drawn for each [1]
correctly shown the name of atom in each molecules [1]
















B
2a
Stomach, Pancreas, Small intestines, Gall bladder.
2 correct [1] 3 correct [2] all [3]

b
Gall bladder store bile which break down large fats molecules into droplets [1] [1]without this organ the person diet should avoid fats [1]

c
Bile makes fats easier to digest [1] / break down large fats droplets to small ones [1]. Lipase digests fats into fatty acids and glycerol[1].

d
Gastric juice in stomach produces hydrochloric acid.Hydrochloric acid is sour[1].
Gastric juice has protease which digests protein into peptones[1].Lumpy mass is because food is not digested fully[1].


3a i
A à Aorta [1] B à Vena Cava [1]

Ii
iii
A -- Oxygenated blood [1] B-- Deoxygenated blood [1]
The oxygenated and deoxygenated blood will be mixed together [1]

b
The blood goes from the heart to the lungs and back again and
blood goes from the heart [1] to the rest of the body and back again [1].



Arteries
Veins
Carry blood from heart
Carry blood to heart
Carry oxygenated blood (except pulmonary artery)
Carry deoxygenated blood (except pulmonary vein)
Thick muscle wall
Thin muscle wall
Narrower lumen
Wider lumen
No valves
Valves present
Carry blood at high pressure/ blood in pulses/ high speed
Carry blood in low pressure/ blood not in pulses/ slow speed

Any one comparison points for both [1] total [5]




4
ai
2 [1]

aii
Day 4, Day 32 [1]

bi
Fertilisation has taken place [1]

bii
the increase in the lining of the uterus in preparation for the growth of the baby.[1]


SECTION C (20 marks) only select 2 questions

C
1a
(i) When mongooses were introduced, they ate the mice which were in abundance. [1] Thus population of mongoose began to increase while the number of mice was reduced. [1] As the number of mice became scarce, the mongoose started to feed on the lizards [1] and ground nesting birds[1] and even snakes [1], thus reducing their population. As a result, the insects population started to grow, causing more harm to the plants [1].


B i
Plants à insects àground nesting birds à snakes àmongooses
Any 2 correct [1] four correct [2] all [3]

ii
Before introducing a species into the habitat, every detail about the species [1], e.g its eating habits , its reproduction rate and impact of that organism on other species [1] (both plants and animals) should be studied.




2

a
To test if the white powder is corn starch, put 2 drop of iodine solution on the powder [1] the yellowish brown iodine solution will changed to bluish black[1]
To test if the white powder is baking soda, add the white powder to a tablespoon of vinegar[1], bubbles are observed [1]
To test if the white powder is sugar, heat the white powder the powder will turned brown then black upon heating [1]
If all the tests above are negative results, the white powder is likely a salt[1]
[1x4=4]

b
As condensation occurs, the gases particles lose energy [1].
The forces of attraction between the particular are stronger and the particles come closer together [1] and re-arranged a liquid state [1] in which the distance between the particles are smaller as compare to the gases particles[1]

3
a
(i)Ovary [1]; Produce eggs and female hormones.[1]
(ii) The other ovary can still produces eggs.[1] The egg from this ovary can still be fertilised.[1]



Millions of sperms deposited into vagina [1]by penis during sexual
intercourse[1].
Sperms swim pass uterus[1] to fallopian tubes and cluster around mature egg[1]. Fertilisation occur in the oviduct [1] when
the fusion of nuclei of sperm and egg[1].

End of paper