Marking scheme Paper 2 Form 5-converted

Marking scheme Paper 2 Form 5
1

Total = 6 marks
2

Total = 6 marks

3a(i) X- S phase 1
Y- Cytokinesis 1

a(ii) - The DNA undergoes replication 1
- A duplicated chromosome consists of two identical sister chromatids 1

b) - Tissue culture technique 1

- The technique involves the growth of the tissues of the wanted banana

plants in suitable medium 1

- The medium contains nutrients , growth hormones and suitable pH, the

whole process is kept under the controlled temperature 1

total 7

4 A(i) J- Inhalation Process K 1
K- Exhalation External intercostal muscles relax, 1
the internal intercostal muscle
A(ii) contract 1
Process J Ribcage moves downwards and
External intercostal muscles inwards 1
contract, the internal intercostal Diaphragm muscles relax and 1
muscle relax return to its resting position
Ribcage moves upwards and
outwards
Diaphragm muscles contract,
Diaphragm lowers and flattens

b - During vigorous physical exercises, human muscles cell contracts 1

repeatedly and rapidly.

- Blood simply cannot supply enough oxygen for aerobic respiration 1

and lactic acid is produced as a by-product when muscles cells carry

out anaerobic respiration

- Lactic acid is toxic and causes muscular fatigue, pain and cramps 1

Only 2

Total 7

5 A(i) Starch 1
Glycogen 1
Cellulose 1
Only
A(ii) U – Condensation 1
V – Hydrolysis 1
1
A(iii) 1
1

-

B(i) 1

B(ii) 1- The reactions of enzymes are specific 1
2- Enzyme are not destroyed after reaction 1
Total 8

6 a) Vessel P: Blood capillaries
b) Vessel Q : lymphatic capillaries

Any 2P
c)

Any 2p
d)

Total = 8 Marks

7 Ai) water 1
Aii) 3

b) Gas Q- Light-independent reaction 12
Gas T- Light – dependent reaction 1

c) Max
3

Total 9

8 a X- active transport 12

Y- Simple diffusion 1

b(i) X-sodium ion 12

Y-Oxygen 1

b(ii) -Y diffuse into the blood capillary following the concentration gradient - 12

because the partial pressure of Y is higher in the alveolus than in the blood 1

capillaries.

c) Advantage 3

It can kept longer 1

Disadvantages

• Certain nutrients in the fruit are lost 1

• The taste of the fruit has changed 1

Total 9

9 Ai)
Aii)

b)

10
ai)

Aii
)
b)

Total = 20 marks

11