Biology Form 2 Topical Revision Questions and Answers (4)

For the preparation of national and local exams, get biology form 2 topical revision questions with answers for free.

These biology topical revision questions are aggregated from the various high school KICD approved textbooks, including KLB biology form 2, Finder biology form 2, Mentors biology form 2, Spotlight biology form 2, Moran biology form 2, Pearsons biology form 2, etc.

The biology topical revision questions with answers cover various topics, as shown below.

The form 2 biological concepts that you can revise with these topical revision questions include;

1. Transport in plants and animals.
2. Respiration.
3. Gaseous exchange.
4. Excretion and homeostasis.

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Questions per topic

1. Transport in Plants and Animals Questions and Answers - Biology Form 2 Topical Revision

Transport in Plants - Questions

1. In an experiment, a leafy shoot was set up in a photometer and kept in a dark room for 2 hours. The set up was then transferred to a well-lit room for 2 hours.
   1. What was the aim of this experiment? (1mk)
   2. Explain the results which would be expected in each of the two experiments conditions. (3mks)
2. Explain how drooping of leaves on a hot sunny day is advantageous to plant. (2mks)
3. Explain how environmental factors affect the rate of transpiration in flowering plants. (20mks)
4. The diagram below represents a transverse section of a young stem.
   
   
   1. Name the parts labeled A and B (2mks)
      A___________________
      B____________________
   2. State the functions of the parts labeled C, D and E
      C________________
      D_______________
      E_______________
   3. List three differences between the section shown above and one that would be obtained from the root of the same plant (3mks)
5. The diagram below represents the pathway of water from soil into the plant.
   
   
   1. Name the structures labeled K and L
      K_______________
      L_______________ (2mks)
   2. Explain how water from the soil reaches the structure labeled L. (5mks)
   3. Name the process by which mineral salts enter into the plant. (1mk)
6. State two ways in which xylem are adapted to their function. (2mks)
7. What makes young herbaceous plant remain upright? (2mks)
8. The diagram below represents part of phloem tissue
   
   
   1. Name the structures labeled R and S and a cell labeled T.
      R ___________________
      S ___________________
      Cell T ___________________ (3mks)
   2. State the function of the structure labeled S. (1mk)
   3. Explain why xylem is a mechanical tissue (2mks)
9. Name the
   1. Material that strengthens xylem tissue. (1mk)
   2. Tissue that is removed when the bark of a dicotyledonous plant is ringed. (1mk)
10. How are xylem vessels adapted for support? (1mk)
11. What is the role of vascular bundles in plant nutrition? (3mks)
12. 1. Name two tissues which are thickened with lignin. (2mks)
    2. How is support attained in herbaceous plant? (1mk)
13. The diagram below represents a transverse section through a plant organ.
    
    
    1. From which plant organ was the section obtained? (1mk)
    2. Give two reasons for your answer in (a) above. (2mks)
    3. Name the parts labeled J, K and L (3mks)
       J__________________________________
       K_________________________________
       L_________________________________
    4. State two functions of the part labeled M. (2mks)
14. Describe how water moves from the soil to the leaves in a tree. (20mks)
15. State two ways in which the root hairs are adapted to their function. (2mks)
16. The diagram below represents a plant tissue.
    
    Name the parts labelled K and L.
    K_________
    L____________
17. In an experiment to determine the effect of ringing on the concentration of sugar in phloem, a ring of bark from the stem of a tree was cut and removed. The amount of sugar in grammes per 16cm3 piece of bark above the ring was measured over a 24 hour period. Sugar was also measure in the bark of a similar stem of a tree which was not ringed. The results are shown in the table below
    

    Time of the day	Amount of sugar in grammes per 16 cm3 piece of bark
    	Normal stem	Ringed stem
    0645	0.78	0.78
    0945	0.80	0.91
    1245	0.81	1.01
    1545	0.80	1.04
    1845	0.77	1.00
    2145	0.73	0.95
    0045	0.65	0.88

    
    
    1. Using the same axes, plot a graph of the amount of sugar against time (6mks)
    2. At what time was the amount of sugar highest in the;
       1. Ringed stem (1mk)
       2. Normal stem (1mk)
    3. How much sugar would be in the rigged stem if it was measured at 0345 hours. (2mks)
    4. Give reasons why there was sugar in the stems of both trees at 06 45 hours. (2mks)
    5. Account for the shape of the graph for the tree with ringed stem between:
       1. 0645 hours and 1545 hours (3mks)
       2. 1545 hours and 0045 hours (2mks)
    6. Other than sugars name two compounds that are translocated in phloem. (2mks)
18. Explain why plants shed off their leaves. (2mks)
19. 1. What is the importance of transpiration to plants?
    2. Give adaptive features which enable a plant to reduce the loss of water.

Transport in Animals - Questions

1. People can die when they inhale gases from burning charcoal in poorly ventilated rooms. What compound is formed in the human body that leads to such deaths? (1mk)
2. Explain why blood from a donor whose blood group is A cannot be transfused into a recipient whose blood group is B. (2mks)
3. State one difference between closed and open circulatory systems. (1mk)
4.  
   1. Give an example of a phylum where all members have
      1. Open circulatory system
      2. Closed circulatory system (2mks)
   2. What are the advantages of the closed circulatory system over the open circulatory system? (5mks)
5. Explain two ways in which mammalian erythrocytes (red blood cells) are adapted to their function (2mks)
6. 1. 1. Name the blood vessels that link arterioles with venules. (1mk)
      2. Explain four ways in which the vessels you named in (a) above are suited to carrying out their functions. (4mks)
   2. State two ways in which the composition of blood in the pulmonary arterioles differ from that in the pulmonary venules. (2mks)
7. Why would carboxyhaemoglobin lead to death? (2mks)
8. Explain how the red blood cells of mammals are adapted for efficient transport of oxygen. (2mks)
9. The chart below is a summary of the blood clotting mechanism in man.
   
   Name
   1. The blood cells represented by X
   2. Metal ion represented by Y
   3. The end product of the mechanism represented Z
10.   
    1. How can excess bleeding result in death? (2mks)
    2. Name the process by which the human body naturally stops bleeding. (1mk)
    3. How can low blood volume be brought back to normal? (2mks)
11.   
    1. Name one defect of the circulatory system in humans. (1mk)
    2. State three functions of blood other than transport. (3mks)
12.   
    1. What prevents blood in veins from flowing backwards? (1mk)
    2. State two ways in which the red blood cells are adapted to their function. (2mks)
13. State one way by which HIV/AIDS is transmitted from mother to child. (1mk)
14. Explain how the various components of blood are adapted for their function. (20mks)
15. Distinguish between blood, plasma, serum, tissue fluid and lymph. (10mks)
    
    
16.   
    1. A patient whose blood group is A died shortly after receiving blood from a person of blood group B. Explain the possible cause of death of the patient. (2mks)
    2. A person of blood group AB requires a transfusion.
       1. Name the blood groups of the possible donors (2mks)
       2. Give reasons for your answer in (i) above. (2mks)
17. Differentiate between active immunity and passive immunity. (2mks)
18. Explain why a person can catch a cold several times in a year but only catches measles once in his or her lifetime. (2mks)
19. Most carbon dioxide is transported from tissues to the lungs within the red blood cells and not in the blood plasma. Give two advantages of this mode of transport. (2mks)
20. What is the importance of tissue fluid? (2mks)

2. Respiration Questions and Answers - Biology Form 2 Topical Revision

1. The diagram below shows a set up that was used to demonstrate fermentation.
   
   Glucose solution was boiled and oil added on top of it. The glucose solution was then allowed to cool before adding the yeast suspension.
   1. Why was the glucose solution boiled before adding the yeast suspension? (1mk)
   2. What was the importance of cooling the glucose solution before adding the yeast suspension? (1mk)
   3. What was the use of the oil in the experiment? (1mk)
   4. What observation would be made in test tube B at the end of the experiment (1mk)
   5. Suggest a control for this experiment (1mk)
2. Give two reasons why accumulation of lactic acid during vigorous exercise lead to an increase in heart beat. (2mks)
3. A process that occurs in plants is represented by the equation below.
   C₆H₁₂O₆ → 2C₂H₅OH + (2CO₂) + Energy
   Glucose        Ethanol    Carbon Dioxide
   1. Name the process (1mk)
   2. State the economic importance of process name in (a) above. (1mk)
4. Other than carbon dioxide, name the other products of anaerobic respiration in plants. (2mks)
5. Name the substance which accumulates in muscles when respiration occurs with insufficient oxygen. (1mk)
6.   
   1. In what form is energy stored in muscles? (1mk)
   2. State the economic importance of anaerobic respiration in plants. (2mks)
7. State four ways in which respiratory surfaces are suited to their function. (4mks)
8.   
   1. A dog weighing 15.2kg requires 216kJ while a mouse weighing 50g requires 2736KJ per day. Explain. (2mks)
   2. What is the end product of respiration in animals when there is insufficient oxygen supply? (1mk)
9.   
   1. Name the products of anaerobic respiration in:
      1. Plants (1mk)
      2. Animals (1mk)
   2. What is oxygen debt? (1mk)
10. 2C₅₁H₉₈O₆ + 145O₂ → 102CO₂ + 98 H₂O + energy
    The above equation shows an oxidation reaction of food substances.
    1. What do you understand by the term respiratory quotient? (1mk)
    2. Determine respiratory quotient of the oxidation of food substance. (2mks)
    3. Identify the food substances. (1mk)
11. Write differences between aerobic respiration and photosynthesis. (4mks)
12. Below is a diagram of an organelle that is involved in aerobic respiration.
    
    
    1. Name the organelle (1mk)
    2. Name the parts labeled A, B, and C. (3mks)
    3. What is the purpose of the folding labeled D? (1mk)
    4. Give the chemical compound which is formed in the organelle and forms the immediate source of energy.

3. Gaseous Exchange Questions and Answers - Biology Form 2 Topical Revision

1. Discuss how gaseous exchange occurs in
   1. Terrestrial Insects (9mks)
   2. Bony fish (11mks)
2.   
   1. Explain how mammalian lungs are adapted for gaseous exchange. (8mks)
   2. Describe how carbon dioxide is produced by
      1. Respiring muscle cells reaches the alveolar cavities in mammalian lungs.
      2. Respiring mesophyll cells of flowering plants reaches the atmosphere. (12 mks)
3.   
   1. Describe the path taken by carbon dioxide released from the tissues of an insect to the atmosphere.
   2. Name two structures used for gaseous exchange in plants. (2mks)
4. Why are gills in fish highly vascularized? (1mk)
5. Describe the
   1. Process of inhalation in mammals. (10 mks)
   2. Mechanism of opening and closing of stomata (10 mks)
6. Name three sites where gaseous exchange takes place in terrestrial plants. (3mks)
7. State two ways in which floating leaves of aquatic plants are adapted to gaseous exchange. (2mks)
8.   
   1. Name two structures for gaseous exchange in aquatic plants. (2mks)
   2. What is the effect of contraction of the diaphragm muscles during breathing in mammals? (3mks)
9. The diagram below represents some gaseous exchange structures in humans.
   
   
   1. Name the structure labeled K, L and M (3mks)
   2. How is the structure labeled J suited to its functions? (3mks)
   3. Name the process by which inhaled air moves from the structure labeled L into blood capillaries. (1mk)
   4. Give the scientific name of the organism that causes tuberculosis in humans. (1mk)
10. State three factors that make alveolus adapted to its function. (3mks)
11. Explain how the alveoli are ventilated.
12.  Explain why water logging of the soil may lead to death in plants. (2mks)
13. Write three advantages of breathing through nose than through mouth. (3mks)
14. State and explain ways the leaves are adapted for gaseous exchange (4mks)
15. Name three gaseous constituents involved in gaseous exchange in plants. (3mks)
16. Name three sites of gaseous exchange in frogs. (3mks)
17.  Name the main site of gaseous exchange in
    1. Mammals
    2. Fish
    3. Leaves
    4. Amoeba (4mks)
18. Name the physiological process by which gas exchange takes place at the respiratory surface in animals and plants (1mk)
19. The diagram below represents a part of the rib cage.
    
    
    1. Name parts labeled W, Y and Z.
    2. How does the part labeled Z facilitates breathing in? (1mk)
20. How is aerenchyma tissue adapted to its function? (2mks)

4. Excretion and Homeostasis Questions and Answers - Biology Form 2 Topical Revision

1. In an investigation the pancreatic duct of a mammal was blocked. It was found that the blood sugar regulation remained normal while food digestion was impaired. Explain these observations. (2 marks)
2.   
   1. Explain why the body temperature of a healthy human being must rise up to 390c on a humid day. (2 marks)
   2. In an experiment a piece of brain was removed from rat. It was found that the rat had large fluctuations of body temperatures suggest the part of the brain that had been removed. (1 mark)
3.   
   1. Explain why sweat accumulates on a person’s skin in a hot humid environment. (2 marks)
   2. Name the specific part of the brain that triggers sweating. (1 marks)
4. Explain why some desert animals excrete uric acid rather than ammonia. (2 marks)
5. State the role of the following hormones in the body
   1. Insulin (3 marks)
   2. Antidiuretic Hormone (3 marks)
6. What osmoregulatory changes would take place in a marine amoeba if it was transferred to a fresh water environment?
7. Name two components of blood that are not present in glomerular filtrate. (2 marks)
8. How would one find out from a sample of urine whether a person is suffering from diabetes mellitus? (2 marks)
9. When is glycogen, which is stored in the liver, converted into glucose and released into the blood? ( 2 marks)
10. A person was found to pass out large volumes of dilute urine frequently. Name the
    1. Diseases the person was suffering from (1 marks)
    2. Hormone that was deficient (1 mark)
11. State the importance of osmoregulation in organisms ( 2 marks)
12. What happens to excess fatty acids and glycerol in the body? (2 marks)
13. Give reasons for each of the following
    1. Constant body temperature is maintained in mammals ( 1 mark)
    2. Low blood sugar level is harmful to the body ( 2 marks)
14. The temperature of a person taken before during and after taking a cold bath. The results are shown in the graph
    
    
    1. Explain why the temperature fell during the bath ( 2 marks)
    2. What changes appeared in the skin that enabled the body temperature to return to normal. (2 marks)
15.   
    1. Name the fluid that is produced by sebaceous glands (1 mark)
    2. What is the role of sweat on the human skin? ( 2 marks)
16. State the role of insulin in the human body? ( 1 mark)
17.   
    1. What is the meaning of the following terms:
       1. Homeostasis ( 1 mark)
       2. Osmoregulation (1 mark)
    2. Name the hormones involved in regulating glucose level in blood
18.    
    1. Explain what happens to excess amino acids in the liver of humans. (3 marks)
    2. Which portions of the human nephrons are only found in the cortex? (3 marks)
    3.   
       1. What would happen if a person produced less antidiuretic hormone? (1 mark)
       2. What term is given to the condition described in (c) (i) above? (1 mark)
19. Define the following terms
    1. Excretion
    2. Secretion
    3. Egestion ( 3 marks)
20. Name the components of blood that do not enter the renal tubule in mammals (2 marks)
21. The table below shows the approximate percent concentration of various components in blood plasma entering the kidney glomerular filtrate and urine of a healthy human being.
    

    Component	Plasma	Glomerular	Urine Filtrate
    Water Glucose Amino Acids Plasma proteins Urea In organic ions	90 0.1 0.05 8.0 0.03 0.72	90 0.1 0.05 0 0.03 0.72	94 0 0 0 2.0 1.5

    
    
    1. Name the process responsible for the formation of glomerular filtrate.
    2. What process is responsible for the absence of glucose and amino acids in urine?
    3. Explain why there are no plasma proteins in the glomerular filtrate
    4. Besides plasma proteins what other major component of blood is absent in the glomerular filtrate.
    5. Why is the concentration of urea in urine much higher than its concentration in the glomerular filtrate?
22. When the environmental temperature is very high, some animals urinate on their legs or lick the sides of their body. How does this help in temperature regulation?
23. Fish are able to use more of their food intake for growth than mammals. Suggest an explanation for this.
24. Explain the term negative feedback
25. Study the diagram below and answer the questions that follow.
    
    
    1. Name the blood vessels labeled A, B and C.
    2. If the animals has recently fed on a diet which is rich in proteins and carbohydrates in which of the vessels labeled A, B, and C would you expect to find the highest concentration of:
       1. Glucose
       2. Amino acids
       3. Carbon (IV) oxide
       4. Oxygen
       5. Urea
    3. During fasting, the level of blood glucose in vessels C may be higher than the level in vessel B explain
26. Describe how the human kidney functions. ( 20 marks)