Candidate

Candidate Name ____________________

TIME 2 hours

INSTRUCTIONS TO CANDIDATES

Write your name, Centre number and candidate number in the spaces at the top of this page and on all

separate answer paper used.

Section AAnswer all questions.

Write your answers in the spaces provided on the question paper.

Section BAnswer any three questions.

Write your answers on the separate answer paper provided.

At the end of the examination,

1 fasten the separate answer paper securely to the question paper;

2 enter the numbers of the Section B questions you have answered in the left hand column of the

' grid below.

INFORMATION FOR CANDIDATES

The number of marks is given in brackets [ ] at the end of each

question or part question.

You are advised to spend no longer than 45 minutes on Section A.

Section A

Answer all questions. Write your answers in the spaces provided on the question paper.1 Fig. 1 shows the stages in the large scale treatment of river water for drinking. The stages are labelled A to F.

A

B

C

D

E

F

Fig. 1(a) Name Stage D. ............................................................... [1](b) Which letter represents the stage at which ultra-violet light kills bacteria? . [1]

(c) Which chemical may be added at C to speed up sedimentation? . [1](d) Which chemical is added at E to destroy any remaining bacteria and viruses?

..

[1]

(e) Why are the storage tanks at F covered?

. [1](f) A chemical which helps reduce tooth decay may be added to the water.State the name of this chemical [1]5096/1 S97

3

2 Fig. 2 shows a generalised animal cell as seen through the electron microscope

Fig. 2

(a) Name, on Fig. 2, the structures labelled A and B.

[2](b) State the parts of the cell responsible for the following processes:(i) forming most of the cell's ATP; ..

(ii) forming proteins from amino acids; ........(iii) storing genetic information; ..(iv) controlling movement of materials in and out of the cell.

. [4]43 Fig. 3 shows a section through a molar tooth.

Fig. 3

(a) Label the parts A, B and C on Fig. 3.

[3](b) Name the part of the tooth where the nerve is found.

[1]

(c) The surface of a tooth is very hard but can be damaged by acids.

Explain the link between a high sugar diet and increased tooth decay. .

[2]5096/1 S97Fig. 4 shows some of the changes in lung volume in a person during different depths of breathing.

Fig. 4

(a) At which point, A, B, C or D, are the following muscles fully contracted?

(i) external intercostal muscles; ...

(ii) internal intercostal muscles; ....

(iii) diaphragm muscle. ................... [3](b) In this person, what are the actual volumes of the:

(i) vital capacity? ................... dm3(ii) residual volume? ................... dm3(iii) tidal volume? ................... dm3[3]5096/1 S976

5Fig. 5 shows two nuclei from a male, dividing, one by mitosis and one by meiosis. Only the sex chromosomes X and Y are shown.

Fig. 5

(a) On Fig. 5, draw in the sex chromosomes as they would appear in nuclei A, B and C. [3](b) What type of cells would contain nuclei B and C? [1](c) Which type of division, mitosis or meiosis, is responsible for:(i) the growth of an organism; .. (ii) variation in a population? .[2]5096/1 S976Fig. 6 shows how blood sugar level is controlled.

Fig. 6(a) Name organs X and Y.

X .

Y.[1]

(b) Name hormones A and B.

A .

B . [2](c) Hormone C is secreted in emergencies. Name hormone C [1]8

7 Fig. 7 shows the life cycle of the house fly.

Fig. 7(a) State two reasons, from the diagram, why the adult house fly, A, is classified as an insect.1 2. [2] (b) Name stage C [1](c) State two ways in which the pupa of the mosquito differs from D, the pupa of the housefly.

1.

2. ..[2]

10Section B

Answer three questions.

Write your answers on separate answer paper provided

8(a) (i) Define diffusion

[2]

(ii) How does active transport defer from diffusion?

[3]

(b) List the end products of digestion of

(i) fats,

(ii) carbohydrates

and state one important use of each in the body.

[4]

(c) Vili are important in both the small intestine and the placenta.

(i) What is a villus?

[2]

(ii) Describe the function of vili in

1. the small intestine,

2. the placenta.

[9]

9(a) Define good health.

[2]

(b) With references to AIDS and lung cancer, explain what meant by

(i) a transmissible disease

[5]

(ii) a non-transmissible disease

[5]

In some cities, homeless children sleep in the under ground sewerages pipes (sewers) at night beg in the streets for food by day. Discuss the health hazards which could result from

(i) sleeping in sewers,

(ii) begging for food.

[8]

10 (a) explain why green plants are known as primary producers.

[6]

(b) (i) Green vegetables are an important part of the balance diet. List three nutrients that they

provide.

[3]

(iii) why is it important to cook green vegetables but not to over cook them?

[3]

(c) State four functions of water in the body.

[4]

(d) (i) State two ways in which the body might lose much water.

[2]

(iii) State two harmful effects on the body of losing too much water.

[2]

11

(a) Fig. 8 shows a kidney tubule.

Fig. 8

(i) Give reasons why the blood pressure is high at A.

(ii) Why is it an advantage for the blood to flow slowly between B and C?(iii) List three substances present at D in the tubule of healthy person.(b) How is oxygen carried by the blood?

(c) Explain how each of the following cause the blood to carry less oxygen,

(i) Plasmodium (the malarial parasite),

(ii) Carbon monoxide.

(a) State how a neurone differs from a nerve.

(b) You touch hot object and immediately take your hand away.

(i) Why is this called a reflects action?

(ii) Describe how this reflex enables you to take your hand away so quickly.

(c) How is the heart beat affected by

(i) the nervous system,

(ii) hormones?

(d) Explain why is it dangerous for a person to drink alcohol before driving a vehicle.

River water

River water

Storage in open reservoir

sedimentation

Storage in open reservoir

A

B

nucleus

ribosome

A

B

C

Hormone A released

From organ X

Glucose converted

To glycogen in

Organ Y

falls

level

normal blood

sugar level

level

rises

Glucose converted

To glycogen in

Organ Y

Hormone B released

From organ X

Rise in blood sugar

Detected by organ X

Fall in blood sugar

Level detected by

Organ X

level

falls

normal blood

sugar level

level

rises