Form 3 Chapter 3

Form 3 Science Chapter 3

FORM 3 CHAPTER 3 EXCRETION

1. Diagram 1 shows the human urinary system.

P: ………………………….

Q: ………………………….

S R: …………………………. Diagram 1

(a) Label P, Q and R on Diagram 1 using the following words. Kidney

Ureter

Urethra [3 marks]

(b) Name the excretory products found in S. ……………………………………………………………………………………………………… [1 mark]

(c) State two functions of the kidney. (i)

…………………………………………………………………………………………… ……

(ii)

…………………………………………………………………………………………… …….

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[2 marks] 2. Diagram 2 shows the structure of a stoma.

P: …………………………

Q: ………………………… Diagram 2

(a) Label P and Q on Diagram 2. [2 marks] (b) On which part of the plant are the stomata found? ……………………………………………………………………………………………………… [1 mark] (c) What is excreted through the stoma during photosynthesis? ………………………………………………………………………………………………………. [1 mark]

(d) What are the excretory products from plants during respiration? …………………………………………………………………………………………….. [1 mark]

(e) Excretory products from plants are also eliminated through the leaves, stems and roots. Name one excretory product from plant which is beneficial to human beings. ………………………………………………………………………………………………………

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Form 3 Science Chapter 3

[1 mark] 3. Diagram 3 shows the human excretory organs.

Q: …………………………..

Human excretory organs

P: …………………………..

R: ………………………….. Diagram 3

(a) Name the excretory organs shown in Diagram 3. [3 marks] (b) How are the excretory products removed from organ Q? ……………………………………………………………………………………………………… [1 mark] (c) Organ R removes wastes from the body by exhaling. What are the contents of exhaled air? ……………………………………………………………………………………………………… [1 mark] (d) Apart from removing wastes from the body, state another function of organ Q.

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Form 3 Science Chapter 3

………………………………………………………………………………………………………. [1 mark] 4. Diagram 4.1 shows the longitudinal section of the kidney.

S: ………………………………. P T: ……………………………..

Q

U: …………………………….. R

Diagram 4.1 (a) Using the following words, label S, T and U in Diagram 4.1. Medulla

Pelvis

Cortex [3 marks]

(b) What is the function of R? …………………………………………………………………………………………………….. [1 mark] (c) State one difference between the blood that flows through P and Q. ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… [1 mark]

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Form 3 Science Chapter 3

(d) Diagram 4.2 shows a machine used by a patient with malfunction of both kidneys.

Blood in

Dialysing fluid in

Partially permeable membrane

Blood out

Dialysing fluid out

Blood clot and bubble trap Diagram 4.2 (i) What is the name of this machine? ………………………………………………………………………………………………… [1 mark] (ii)

Explain briefly how this machine works. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. [2 marks]

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Form 3 Science Chapter 3

5. Diagram 5 shows the human excretory system.

P: ……………………….

Q: ………………………. R: ………………………..

Diagram 5

(a) On Diagram 5, label P, Q and R with the following words. Lung

Skin

Kidney [3 marks]

(b) Draw lines to show the correct match between the excretory organs and their excretory products. The answers can be used more than once. Draw the lines as shown below. Excretory organ

Excretory products

Urea, water and mineral salts P Urea and water Q Carbon dioxide and water R

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Form 3 Science Chapter 3

[2 marks]

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