Biology Form 2 End Term 2 Exams 2021 with Marking Schemes

1. The equation bellows shows a chemical reaction that takes place in green plants under certain conditions
   
   Carbon (IV) Oxide + Water Glucose + X
   
   
   1. Name the; (2mks)
      1. Process represented by the equation
      2. Substance represent by X...
   2. Other than the reactants, state two conditions necessary for this reaction to occur. (2mks)
   3. Name three types of cells in which the process occurs (3mks)
2. Name one example of the specialized cells in plants and one example in animals.
   
   1. Plants. (1mk)
   2. Animals.(1mk)
3. Identify the following apparatus and state its functions.
   
   
   1. Name.(1mk)
   2. Function (1mk)
4. A student measured the length of a mitochondrion on a photomicrograph whose magnification was X 40000 and found it to be 1mm. Calculate the actual size of the mitochondrion. (3mks)
5. State the type of solution that makes the plant cell. (2mks)
   
   1. Flaccid........
   2. Turgid
6. Name the carbohydrate stored in: 
   
   1. Cell wall. . (1mk)
   2. Mammalian liver. . (1mk)
7. Study the reaction below and answer the questions that follow.
   
   
   1. What biological processes are represented by A and B? (2mk)
   2. Identify the product Y (1mk)
   3. State the bond represented by X .......(1mk)
8. The figure below represents a structure obtained from the ileum of a mammal.
   
   
   1. Give the identity of the structure. (1 mk)
   2. What is the importance of the structure named in (a) above? (1 mk)
   3. Name the parts labeled A, B and D. (3mks)
9.  
   1. Name the juice secreted by the part labeled C. (1mk)
   2. List two enzymes present in the juice named in d (i) above. (2mks)
10. What are the structural differences between veins and arteries? (3mks)
11. State three differences between aerobic and anaerobic respiration. (3mks)
12.  
    1. Name the type of immunity developed by the body when one is vaccinated against a certain disease (1mk)
    2. Name the blood groups of a person whose blood plasma has antibody b (2mks)
    3. State the role of thrombin in blood clotting (1mk)
13.  
    1. Define respiration (1mk)
    2. Study the equation below. Identify the process represented below (1mk)
       
       C₆H₁₂O₆ -> 2C₂H₅OH + CO₂ + 210KJ
       
       
    3. Name an organism this process may occur.(1mk)
    4. Identify the food substrate of whose respiratory quotient (RQ) was found to be 0.7 (1mk)
14. State the functions of the following hormones 
    
    1. Antidiuretic hormone (2mks)
    2. Glucagon (2mks)
15. Outline three ways in which the gills of Tilapia fish are modified to perform their function (3 mks)
16.  
    1. Calculate the respiration quotient (RQ) from the equation below:- (3 mks) 2C₅₁H₉₈O₆ + 145O₂ -> 102 CO₂ + 98H₂O + Energy
    2. Identify the substrate being respired in the above equation (1 mk)
17.  
    1. Explain what is meant by the term oxygen debt in human beings (2 mark)
    2. What are the end products of anaerobic respiration in animals (2 mrks)
18.  
    1. Where in a cell does glycolysis take place? (1mrk)
    2. Name the product of the above process (1mrk)
       
       
19. The equation below summarizes a metabolic process in plants.
    
    Glucose -> Ethanol + carbon (IV) oxide + Energy
    
    State two industrial applications of the above equation. (2mks)
    
    
20. Explain why a rat, though small eats more frequently than an elephant (2mks)
21. Give the conditions necessary for the second phase of aerobic respiration (3mks)
22. Name any three respiratory diseases (3mks)
23. Briefly explain the process of inhalation in man. (8mks)

Marking Scheme

MARKING SCHEME BIO FORM TWO

1.  
   1.  
      1. Photosynthesis
      2. Oxygen
   2.  
      • Presence of light ;
      • Presence of chlorophyll;
      • Presence of suitable temperature ;
   3.  
      • Palisade cells;
      • Guard cells;
      • Spongy mesophyl ;
      • Palisade mesophyl;
2.  
   • In plants- Guard cells; root hair cells; palisade cells
   • In animals- sperm cell; white blood cells; Red blood cells; nerve cells.
3.  
   1. pair of forceps’;
   2. picking up small stinging crawling animals;
4.  
   
5.  
   1. Hypertonic solution; acc. Highly concentrated solution (1mk)
   2. Hypotonic solution; acc. More dilute solution;
6.  
   1. Cellulose;
   2. Glycogen;
7.  
   1. A – Condensation;  B – Hydrolysis;
   2. Sucrose;
   3. Glycosidic;      (1mk)
8.  
   1. Villus
   2. Increases the surface area for absorption of digested food substances/materials
   3. A-microvilli
      B – Lacteal
      D-Arteriole
9.  
   1. Succus entericcus/intestinal juice
   2. Polypetidase, sucrose, lactase, lipase,
10.  
    

    Arteries	Veins
    Narrow lumen Thicker muscle layer No valves along length More elastic	Wide lumen Thinner muscle layer Have valves along length Less elastic.

    
    
    
11.  
    

    Aerobic	Anaerobic
    Oxygen is used. Breakdown is complete to CO2 and water. More energy released. Water molecules produced. Occurs in the cytoplasm and mitochondria. End products the same in plants and animals. (water, CO2)	Oxygen not used Breakdown incomplete to ethanol or lactic acid. Less energy released Water molecules are not produced. Occurs in the cytoplasm. End products not the same in plants – ethanol in animals – lactic acid

    
    
    
12.  
    1. Artificial immunity
    2. A, O
    3. Activates the conversion of fibrinogen to fibrin
13.  
    1. Respiration is the process by which food substances are chemically broken down in all living cells to release energy, carbon (IV) Oxide and water.
    2. Anaerobic respiration
    3. Plants
    4. Lipids
14.  
    1. Increases the permeability of tubule and blood capillaries to water; regulates the reabsorption of water
    2. Stimulates liver cells to convert glycogen into glucose
15.  
    • Gill rakers act as a screen preventing entry of food and other particles that might damage the delicate gill lamella;
    • Gill bar for attachment of gill rakers and gill filament
    • Gill filaments – the surface on which gaseous exchange take place
16.  
    1. RQ =
       Vol of CO2 produced 
         Vol. of O2 used 
       =102
          145
       
       = 0.70
    2. Lipids;
17.  
    1. Amount of oxygen required to get rid of lactic acid that accumulates in the body tissues when oxygen available is lower than the demand
    2. Energy/A.T.P/ Lactic acid
18.   
    1. 1. Cytoplasm
       2. Pyruvic acid
    2. Pyruvic acid is broken down; into ethanol and CO₂
19.  
    • baking of bread
    • brewing industry
20. A  rat has  a large surface  area  to  volume ratio thus  loses a lot  of  energy   on form of  heat therefore  eats a lot  to replace  the  lost energy;
21.  
    • cells must be provided with glucose or food
    • oxygen must be taken in to react with glucose
    • favorable temperature should be maintained for efficient enzyme functioning
    • end products must be continuously be eliminated from the mitochondrion
22. asthma;bronchitis;whooping cough; tuberculosis
23. External intercostals muscles contract; internal intercostals muscle relax; Rib cage   move outwards; and upwards; Diaphragm muscles contract; diaphragm flatten; Volume in thoracic cavity increases; pressure reduces;  Atmospheric air enters the lungs; lungs inflate;