SSCE/WASSCE/GCE PASS QUESTIONS AND ANSWERS ON TRANSPORT IN MAMMALS

SSCE/WASSCE/GCE PASS QUESTIONS AND ANSWERS

OBJECTIVES/ MULTIPLE CHOICES

1.      Which of the following sequences is a brief outline of systematic circulation?

A.    Heart ® Lungs ® cells

B.     Lungs ® Heart ® Body

C.     Heart ® cells ® Lungs

D.    Heart ® Body ® Hearts 

2.      Veins are equipped with valve because

A.    They have a relatively wider lumen than arteries

B.     They transport blood towards the heart

C.     There is tendency for back flow of blood in veins during diastole 

D.    The volume of blood transported by veins is relatively larger

3.      The tricuspid valve is located between the  

A.    Left and right auricles

B.     Right and left ventricles

C.     Right auricle and right ventricle

D.    Right ventricle and right auricles

4.      Aged erythrocytes are dissolved in the

A. pancreas      

B. liver       

C. lymph nodes      

D. kidney

5.      Fibrinogen and prothrombin play important roles in the

A. deamination of proteins

B. clotting of blood

C. detoxication of substance

D. storage of vitamins

6.      Deoxygenation blood flows into the right and left lungs through the

A. pulmonary vein     

B. vena cava        

C. pulmonary artery       

D. subclavian vein

7.      Which vitamin plays an important role in blood clotting?

A. vitamin A                

B. Vitamin K        

C. Vitamin B12       

D. Vitamin C

8.      Which of following is NOT involved in the transport of substance in the body?

A. Lymph                   

B. Plasma            

C. Leucocytes       

D. Erythrocytes

9.      In mammals, the exchange of nutrients and metabolic products occurs in the

A. lymph                 

B. lungs         

C. heart         

D. liver

10.  The element that is essential for the coagulation of blood is

A. potassium             

B. calcium            

C. phosphorus    

D. iron

11.  In adult mammalian blood, the cells which lack nuclei are the

A. erythrocytes             

B. lymphocytes      

C. leucocytes      

D. phagocytes

12.  In blood transfusion, agglutination occurs when

A. white blood cells from two individuals meet

B. two different antibodies meet

C. two different antigens meet

D. contrasting antigens and antibodies meet

13.  The lymphatic system of mammals rejoins the blood circulatory system at the

A. hepatic vein       

B. subclavian vein

C. renal vein   

D. common iliac vein

14.  In dissection, the rib cage of mammal has to be opened in order to expose the

A. diaphragm            

B. liver               

C. heart       

D. sternum

15.    The chamber of the mammalian heart with the thickest wall is the

A. right ventricles        

B. left auricle           

C. right auricle        

D. left ventricle

16.    Serum differs from cells and fibrinogen

A. contains blood cells and fibrinogen

B. contains soluble food and mineral salt

C. lacks the blood protein, fibrinogen

D. lacks blood cells and albumin

17.    The transportation of oxygen and carbon (IV) oxide in mammals is carried out by

A. leucocytes                 

B. thrombocytes        

C. phagocytes     

D. erythrocytes

18.    The mammalian erythrocytes differ from the leucocytes at maturity because the erythrocytes are

A. discoid and nucleated

B. discoid and enucleated

C. amoeboid and nucleated

D. amoeboid and enucleated

19.    Which of the following pairs of organs are located in the anterior half of the mammalian body cavity?

A. Kidneys and lungs 

B. Heart and ovary   

C. Lungs and heart     

D. Kidneys and heart

20.    The only vein that carriers pure oxygenated blood is the

A. renal vein                

B. pulmonary vein       

C. hepatic vein  

D. sciatic vein

Answers

1. D	6. C	11. A	16. C
2. C	7. B	12. D	17. D
3. C	8. C	13. A	18. B
4. B	9. A	14. C	19. C
5. B	10. B	15. D	20. B

THEORY

1.      (SSCE, 1994) (i) How does the structure of the artery and the vein enable each of them to carry it function.

(i)        List four functions blood

Solution

Arteries: possession of thick elastic walls and narrow lumen helps to withstand the pressure of blood that flows in them.

Veins: presence of wide lumen and valves prevent the back flow of blood.

Functions of blood 

1. Temperature regulation

2. Transports food and oxygen 

3. Transports hormones  

4. Removes carbon dioxide and nitrogenous waste

5. Brings about clotting of blood to prevent excessive loss of blood when wounded

2. (SSCE, 1999) (a) Describe the composition of the mammalian blood.

(b) State four categories of functions of the mammalian blood.

 

Solution 

Blood consists of Cellular and liquid components. The liquid part of blood is called plasma.  It is a pale yellow fluid that consists of about 91% water and 9% other substances, such as proteins, ions, nutrients, gases and waste products. Water acts as a solvent which dissolves and suspends solutes of blood and also absorbs heat.

The cellular components are subdivided into;

1. Erythrocytes (Red Blood Cells)

2. Leukocytes (White Blood Cells)

3. Thrombocytes (Platelets)

Red blood cells are biconcave discs, flattened, small cells but no nucleus. The red blood cell contains pigmented protein called haemoglobin, the protein that binds oxygen.

White blood cells are irregular in shape, contain nuclei, mitochondria and can move in an amoeboid fashion. Leukocytes that have granules in the cytoplasm are called granulocytes and are of three types i.e. neutrophils, eosinophils and basophils. Those without clearly visible granules are called Agranulocytes and are of two types i.e. lymphocytes and monocytes.  

Platelets are minute fragments of cells consisting of small amount of cytoplasm surrounded by a plasma membrane. 

(b) Four categories of function of blood

1. Transport: carries oxygen, nutrients, hormones, wastes products, metabolic heat from one part of the body to another. 

2. Protection: white blood cells destroy some microorganisms and cancerous cells.

3. Clotting of blood: platelets help in clotting of blood to minimize excessive blood loss.

4. Regulation: Blood transfers water or ions or heat to and from the tissues which help to stabilize the water content or pH or body temperature respectively.

3.       (SSCE, 2002 Q6) (a)(i) Name the cellular components of the human blood.

(ii) State the site of formation of each cellular components of blood.

(iii) Give the function of each of the cellular components of blood.

(b) Explain how the mammalian heart functions. 

Solution

(a)(i) Refer to Blog content

(ii) Site of formation

1. Erythrocytes: Bone marrow

2. Lymphocytes: Lymph node  

3. Platelets: Bone marrow

4. Phagocytes: Bone marrow

(iii) Functions

1. Erythrocytes: transport oxygen from the lung to all parts of the body and small quantity of CO₂ from tissues to lungs

2. Platelets: involved in blood clotting

3. Lymphocytes: antibody production

4. Phagocytes: ingestion of foreign materials

(b) Functioning of mammalian heart

The heart function is of two patterns; contraction and relaxation.  The contraction phase is called systole and relaxation phase is called diastole. When the two atria contract the blood is forced into the relaxed ventricles. After a slight pause, the two ventricles contract, forcing the blood into the arteries. The backflow of blood into the atria is prevented by the sudden closing of the tricuspid and the bicuspid valves. The closing of these valves produces a loud “lub” sound which we can hear in a heartbeat.

After the ventricles have fully contracted, they start to relax. As they relax, the blood in the arteries tends to flow back into the ventricles. This is prevented by the sudden closing of the semi-lunar valves which produces a soft “dub” sound. A systole and a diastole make up one heartbeat.

 

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