SSCE/WASSCE/GCE PAST QUESTIONS AND ANSWERS ON EXCRETION IN MAMMALS
SSCE/WASSCE/GCE PAST QUESTIONS AND ANSWERS
OBJECTIVES/ MULTIPLE CHOICES
1. Which of the following substances is usually absent in the urine of a healthy person?
A. Salts
B. Water
C. Urea
D. Glucose
2. The nephridia in the earthworm form part of the
A. reproductive system
B. respiratory system
C. circulatory system
D. excretory system
3. When it is cold, the blood vessels of the skin
A. dilates to increase the amount of blood flowing
B. constrict to reduce the amount of blood flowing to the skin
C. dilate to reduce the amount of blood flowing to the skin
D. constrict to increase the amount of blood flowing to the skin
4. The process of deamination is essential for the
A. digestion of protein
B. secretion of bile
C. formation of urea
D. formation of antibody
5. Regulation of blood sugar level takes place in the
A. pancreas
B. ileum
C. liver
D. kidney
Use the diagram to answer question 6 & 7
6. The parts labelled I and II make up the
A. glomerulus
B. convoluted tubules
C. Malpighian body
D. Bowman's capsule
7. In mammals, reabsorption of salt takes place in
A. IV
B. III
C. II
D. I
8. Urea formation occurs in the
A. heart
B. liver
C. lung
D. kidney
9. Metabolic production of urea is carried out in the
A. urinary bladder and kidney
B. Liver
C. Pancreas
D. Kidney and malphigian tubule
10. The urinary tubules of the kidney function through
A. osmosis and diffusion
B. active transport and osmosis
C. ultrfiltration and selective reabsorption
D. active transport and cytoplasmic streaming
11. Which of the following is a homeostatic response in humans?
A. Withdrawing the hand from a hot object
B. The mouth getting watery when food is sighted
C. yawning owing to tiredness
D. shivering in a cold environment
12. Which of the following is a homeostatic response in humans?
A. Withdrawing the hand from a hot object
B. The mouth getting watery when food is sighted
C. yawning owing to tiredness
D. shivering in a cold environment
13. The product of excretion common to the mammalian kidney, lung and skin is
A. mineral salt
B. carbon (IV) oxide
C. water
D. urea
14. The part of the mammalian skin involved in temperature regulation is the
A. sweat gland
B. hair papilla
C. hair follicle
D. sebaceous gland
15. In the mammalian kidney, the Bowman''s capsules is located in the
A. ureter
B. pelvis
C. cortex
D. medulla
Use the diagram below to answer question 16 & 17
16. Bowman's capsule is located in the part labelled
A. I
B. II
C. III
D. IV
17. Reabsorption of useful materials takes place in the part labelled
A. I and III
B. III and V
C. V and VI
D. II and IV
18. Which of the following parts of the mammalian skin is directly involved in excretion?
A. Sebaceous gland
B. Sweet gland
C. Hormy layer
D. Hair follicle
19. The pigment in the malphigian layer responsible for skin colouration is known as
A. haemoglobin
B. haemocyanin
C. chlorocruorin
D. melanin
20. Which of the following structures functions as an excretory, system found in flatworm?
A. Contractile vacuole
B. Nephridium
C. Flame cell
D. Malplghlan tubule
Answers
|
1. D |
6. D |
11. D |
16. B |
|
2. D |
7. B |
12. D |
17. D |
|
3. B |
8. B |
13. C |
18. B |
|
4. C |
9. D |
14. A |
19. D |
|
5. C |
10. C |
15. D |
20. C |
THEORY
1. (SSCE 1993 Q3) (a) What is meant by the term homeostasis? Mention two examples of the process
(b) (i) How does the skin function as a homeostasis organ?
(ii) List the excretory products removed by kidney
Solution
(a) Refer to blog
(b) (i) ) Skin as homeostatic organ, regulates body temperature.
When the body temperature is low (cold weather);
Refer to blog
When the temperature of the body is high (hot weather);
Refer to blog
(ii) The kidney excretes urea, uric acid, mineral salts, water and urine.
2. (SSCE 1995 Q4) Explain how each of the following enables a mammal to maintain a constant body temperature.
(i) Shivering
(ii) Sweating
(iii) Hair
(iv) Blood capillaries
Solutioni)
Shivering
It occurs in cold weather or when the temperature is low and the body needs to be warmed. It is a spontaneous muscle contraction which raises the temperature of the body. The muscles use up metabolite and produce heat.
ii) Sweat
This occurs when the body is over heated. The rate of sweat production increases with the result that more heat is taken form the cells of the skin to evaporate the water in the sweat. As more heat of vaporization is taken from the skin the temperature falls.
iii) Hair
In cold weather the erector muscles of the hair make the hair stand perpendicular to the skin. This causes a layer of air to be trapped on top of the skin to prevent heat loss.
iv) Blood capillaries in the skin
In cold weather, arterioles in the surface of the skin constrict. This effect called vasoconstriction, reduces the volume of warm blood flowing near to the skin surface, bringing about a considerable reduction in the loss of heat.
In hot weather when the body is overheated, the arterioles in upper reaches of the skin dilates (vasodilation). More warm blood is brought near to the surface of the skin and subsequently more heat is lost to the environment.
3. (SSCE 1998 Q4) (a) (i) What is excretion?
(ii) List the excretory products of mammals and indicate where each product is formed.
(b) (i) Make a labeled diagram of the nephron of a mammal.
(ii) How does the structure of the nephron suit its function?
Solution
(a) (i) Refer to blog
(ii) Excretory products & site of formation
Excretory products
Sites of production
Carbon dioxide
Body cells and tissues
Urea or nitrogenous substances
Liver
Excess water and salts
Body cells and tissues
Bile pigments
Liver
(b) (i) Drawing of a Nephron
(iii)
1. The Bowman’s capsule funnels the filtrate into tubules.
2. The glomerulus provides large surface area for ultrafiltration.
3. Proximal and distal convoluted tubules provide surface area for absorption of nutrients, salts and water.
4. Sodium pump mechanism occurs in the loop of Henle
5. Network of blood capillaries surround convoluted tubules for reabsorption.
6. Collecting duct collect urine
3. (SSCE 1999 Q4) (a) List the main excretory products in the body of mammal.
(b) Describe how urine is formed in the kidney of a mammal. Support your answer with a diagram.
Solution
1. Carbon dioxide
2. Mineral salts
3. Excess water
4. Bile pigments.
5. Nitrogenous substances
(b) Urine formation in the kidney
Refer to blog
Diagram (Drawing of a Nephron)
4. (SSCE, 2000 Q6) (a) What is the significance of homeostasis?
(b) Indicate the part played by each of the following organs in the homeostatic mechanism of mammals.
(i) kidney
(ii) skin
(iii) liver
Solution
(a) Refer to blog contents
(b) (i) Refer to blog content
(ii) Skin (Refer to Q3 SSCE 1993)
(iii) Refer to blog content (role of liver in homeostasis)
5. (SSCE, 2004 Q2) (a) (i) Explain briefly the term homeostasis.
(ii) Name the organs in the mammalian body that are concerned with homeostasis
(b) Describe how constant body temperature is maintained in a mammal
Solution
(a) (i) & (b) Refer to Q3 SSCE 1993
(ii) Skin, liver, lungs, and kidney
6. (WASSCE, 2006 Q4) (a) List three excretory organ in mammals and one product excreted by each.
(b) Name the excretory organs found in
(i) Insects
(ii) Nematodes
(iii) Paramecium
(c) State the similarities between a skin and a leaf
(d) Describe urine formation in man.
Solution
(a)
Organ | Excretory products |
Lungs | Carbon dioxide/water |
Liver | Urea/bile pigments/salts/ excess cholesterol |
Skin | Sweat/urea/water/salt |
Kidney | Salts/water/urea |
(b) (i)
1. Insects: malpighian tubules
2. Nematodes: flame tubules
3. Paramecium: contractile vacuole
(c)
|
Skin |
Leaf |
|
Presence of epidermal layer |
Presence of epidermal layer |
|
Presence of hairs on epidermal layer |
Presence of hairs on some leafs |
|
Sweat pores for elimination of water |
Stomatal pores for release of water |
|
Blood vessels form transport system |
Transport system present as conducting vessels. |
(d) Refer to Q4 SSCE 1999
7. (WASSCE, 2007 Q5) (a) Name the excretory organs in:
(i) Amoeba
(ii) Earthworm
(iii) Insects
(b) List the excretory organs in humans and name one waste products in each case.
(c) Make a drawing 10-12cm long of the nephron and label fully.
Solution
(a) Excretory
organ
|
Amoeba
|
Contractile
vacuole |
|
Earthworm
|
Nephridium
|
|
Insects
|
Malpighian
tubules |
(b) Refer to blog content
(c) Drawing of nephron
Refer to blog content