KCSE 2014 Biology Paper 1 Questions with Marking Scheme

QUESTIONS

Answer all the questions.

1. State the importance of each of the following living organisms:
   
   1. nutrition (1 mark)
      
      
   2. excretion (1 mark)
      
      
2. 1. What is meant by the term seed dormancy? (1 mark)
      
      
   2. State three causes of seed dormancy. (3 marks)
      
      
      
3. State two functions of the placenta in mammals. (2 marks)
   
   
4. The diagram below illustrates a growing pollen tube.
   
   
   
   
   1. Name the part labelled B. (1 mark)
      
      
   2. Explain the role of the parts labelled A. (2 marks)
      
      
5. The diagram below shows a set up for an experiment to demonstrate a certan physiological process.
   
   
   
   
   1. What nature of solution is represented by 20% sugar solution? (1 mark)
      
      
   2. Explain the observation made on the set up after one hour. (2 marks)
      
      
6. State three roles of auxins in a plant stem. (3 marks)
   
   
7. A student drew a 6cm long diagram of a plant flower. If the actual length of the flower was 12cm, calculate the magnification of the drawing made by the student. Show your working. (2 marks)
   
   
8. Differenciate between phenotype and genotype as used in genetics. (1 marks)
   
   
9. State two functions of intervertebral discs in the mammalian skeleton. (2 marks)
   
   
10. 1. Explain two roles of diffusion in human beings. (4 marks)
       
       
    2. What is meant by each of the following terms?
       
       1. Crenated cell (1 mark)
       2. Flaccid cell (1 mark)
          
          
11. State three differences between tactic and tropic responses. (3 marks)
    
    
12. The diagram below represents a model used to demonstrate breathing in mammals.
    
    
    
    
    1. Name the mammalian structure represented by the parts labelled D and E.
       1. D ( 1 mark)
       2. E (1 mark)
          
          
    2. State the observation made when the string is pulled downwards. (1 mark)
       
       
    3. Explain the observation in (b) above. (2 marks)
       
       
13. State one function of each of the following parts of the mammalian eye:
    1. eye lashes (1 mark)
       
       
    2. lachrymal glands (1 mark)
       
       
14. State three structural differences between DNA and RNA. ( 3 marks)
    
    
15. 1. Which type of mammalian muscles is voluntary. (1 mark)
       
       
    2. Distnguish between tendon and ligament. (1 mark)
       
       
16. The diagram below illustrates a nerve cell.
    
    
    
    
    1. Name the type of nerve cell illustrated. (1 mark)
       
       
    2. Give a reason for your answer in (a) above. (1 mark)
       
       
    3. Identify the part labelled J. (1 mark)
       
       
    4. State one function of each of the parts labelled G and H.
       1. G (1 mark)
       2. H (1 mark)
          
          
17. Give a reason why the image is not formed when light is focused on the blind spot. (1 mark)
    
    
18. Explain why
    1. mammalian testes are located to hang outside the body. (2 marks)
       
       
    2. four months after fertilisation, ovaries can be removed from a huma n female, without terminating pregnancy. (2 marks)
       
       
19. Why is a burning charcoal stove in a poofy ventilated room likely to cause death of the inhabitants? (3 marks)
    
    
20. State one function of each of the following cell organelle:
    1. golgi bodies (1 mark)
    2. lysosomes (1 mark)
       
       
21. Name the type of skeleton that amkes up each of the following animals:
    1. locust (1 mark)
       
       
    2. bird (1 mark)
       
       
22. 1. Name two vestigial structures in human beings. (2 marks)
       
       
    2. Why are some bacteria unable to resist the effect of antibiotics? (2 marks)
       
       
23. Below is an illustration of a cross section of a plant root showing the transportation of substances in the plant.
    
    
    
    
    1. Name the substances transported along the parts labelled K and L.
       K (1 mark)
       L (1 mark)
       
       
    2. Give a reason for your answer in L above. (1 mark)
       
       
24. The diagram below shows the transportation of substances in a human body.
    
    
    
    Name the substances represented by
    M (1 mark)
    N (1 mark)
    P (1 mark)
    
    
25. State two roles of luteinising hormone in human reproduction. (2 marks)
    
    
26. The table provided shows the concentration of sodium and iodine in sea water and cell sap of plant.
    
    
    
    
    1. 1. Name the process through which plant cells take up sodium ions. (1 mark)
       2. Give a reason for your answer in (a) (i) above. (1 mark)
          
          
    2. If the plant was sprayed with with a chemical that inhibits respiration:
       1. which of the two ions uptake will be affected? (1 mark)
       2. give a reason for your answer in (b) (i) above. (1 mark)
          
          
27. The diagram below shows the gaseous exchange system of a locust.
    
    
    
    
    1. Name the structure labelled Q. (1 mark)
       
       
    2. State the function of the part labelled R. ( 1 mark)
       
       
    3. How is the part labelled S structurally adapted to its function? (2 marks)

MARKING SCHEME

1.                      
   1. Acquisition and utilization of nutrients; (1 mark)
   2. Elimination of metabolic wastes to prevent accumulation to toxic level;(1 mark)
2.              
   1. A period of rest in which a seed performs its physiological processes slowly and utilizes little food; (1 mark)
   2.                
      • Chemical/growth inhibitors;
      • Hard/impermeable seed coat;
      • Low / freezing temperatures;
      • Under developed embryo/immature embryo;
      • Low concentration of hormones;
      • Lack of appropriate light wavelength;
        (max 3 marks)
3.            
   • Exchange of nutrients /metabolic wastes/gases between the mother and foetal circulatory systems;
   • Secretion of progesterone hormone;
     (2 marks)
4.                  
   1. Tube nucleus;
   2.                  
      • One male nucleus fuses with the egg cell nucleus to form a zygote;
      • The other male nucleus fuses with the polar nuclei to form the endosperm;
        (2 marks)
5.                        
   1. Hypertonic solution; (1 mark)
   2. Volume of sugar solution increases in the thistle funnel while that of distilled water in the beaker reduces; because the thistle funnel gains distilled water by osmosis.(2 marks)
6.                  
   • Cell division;
   • Cell elongation;
   • Development of adventitious roots;
   • Formation of callus tissue;
   • Causes apical dominance;
   • Causes tropic responses.
     3 x 1 (3 marks)
7. Object length = 12 cm
   Drawing length = 6 cm
   Mg = Drawing length ; = 6 
            Object length        12
   = X 0.5;
   (2 marks)
8. Phenotype is the outward appearance of an organism while Genotype is the genetic make up of an organism; (1 mark)
9. Act as shock absorbers;
   Allow smooth movement between the vertebrae/reduce friction;
   (2 marks)
10.            
    1.                  
       • Absorption of materials e.g. diffusion of digested food into the blood stream;
       • Gaseous exchange e.g. CO2/O2 diffuses from capillaries into the alveoli.
       • Excretion of nitrogenous wastes; e.g urea diffuses from blood capillaries into the elimination sites. (max 4 marks)
    2.              
       1. Crenated cell is a shrunk animal cell that has lost water by osmosis;(1 mark)
       2. Flaccid cell is a flabby /shrunk plant cell that has lost waster by osmosis;(1 mark)
11.                    
    

    Tactic Responses	Tropic Response
    Are locomotory	Are growth responses;
    Are fast	Are slow
    Not influenced by growth hormones	Are caused by growth hormones;
    Temporary	Permanent

    (3 marks)
12.                      
    1.                          
       1. Rib-cage/chest cavity; (1 mark)
       2. Diaphragm; (1 mark)
    2. The balloons are inflated; (1 mark)
    3. Pulling down the string increases the volume of D, hence decreasing the pressure inside;
       The low pressure causes external atmospheric air to rush in and inflate the balloons;
       (2 marks)
13.                
    1. Trap foreign particles entering the eye;
       Produce fluid/tears; (1 mark)
    2. Moistens the cornea;
       Wash foreign materials out of the eye;
       Antiseptic / kills harmful microorganisms; (max 1 mark)
14.                                            
    

    DNA	RNA
    Double stranded/double relix	Single stranded;
    Has Thymine	Thymine is replaced by uracil/reject Thiamin;
    Has the four nitrogen base pairing pattern	Lack the four nitrogen base pairing pattern;
    Deoxyribose sugar	Ribose sugar;

    (3 marks)               
15.                          
    1. Skeletal muscles / striated muscles; (1 mark)
    2. Tendon is a (inelastic) tissue that attaches muscles to bones while Ligament is a (inelastic) tissue that attaches a bone to another bone of a movable joint;(1 mark)
16.                
    1. Sensory neurone; (1 mark)
    2. Cell body is located off the axon/tied outside the CNS; (1 mark)
    3. Schwann cell; (1 mark)
    4.                        
       1. Receipt/transmits impulses to neighbouring neurons in the CNS from sense organs; (1 mark)
       2. Insulates the axon/accept dendron for axon; (1 mark)
17. The blind spot lacks both cones and rods hence images are not perceived; (1 mark)
    Accept photoreceptor cells for cones and rods;
18.                    
    1. To provide a cool environment; that is conducive for sperm formation; (2 marks)
    2. Progesterone hormone; is secreted by the placenta to maintain the pregnancy;
19. Due to limited oxygen, haemoglobin combines with carbon (II) oxide to form carboxyhaemoglobin;(2 marks)
    Carboxyhaemoglobin does not readily dissociate hence reduces the capacity of haemoglobin to transport oxygen; Carbon (II) oxide is therefore a respiratory poison if breathed in for a long time;(3 marks)
20.                      
    1. Packaging of substances/glycoproteins/ transportation of glycoproteins;
       Secretion of synthesized proteins and carbohydrates;
       Formation of lysosomes/modification of carbohydrates to form glycoproteins;
       (1 mark)
    2. Digestion of food/Breakdown large molecules;
       Destroy worn out organelles or cells/tissue;
       (max 1 mark)
21.                
    1. Exoskeleton; (1 mark)
    2. Endoskeleton; (1 mark)
22.                          
    1. Appendix/accept nictating membrane; coecum and ear drum;
       Tail/coccyx; (1 mark)
    2. They have a gene for resistance/acquire it through mutation;
       The gene for resistance is passed to offsprings establishing a population of resistant forms;
       (2 marks)
23.                
    1. K - Photosynthetic products/manufactured foods example vitamins/alicose/proteins/ sucrose/maltose/fructose/lipids/nitrates; (1 mark)
       L - Water and mineral salts; (1 mark)
    2. The substances are moved into the star shaped xylem; (1 mark)
24. M - lungs; (1 mark)
    N - Urea, ammonia, ; (1 mark)
    P - Digested food, water; mineral ions; (1 mark)
25.                      
    • Stimulates maturation of the Graafian follicle/stimulates ovulation;
    • Stimulates corpus luteum to secrete progesterone hormone;
    • Stimulates release of androgens;
    • Stimulates development of corpus luteum;
      (2 marks)
26.                
    1.                
       1. Diffusion; (1 mark)
       2. Sea water contains a higher concentration of sodium ions than the cell sap; (1 mark)
    2.              
       1. Iodide ions; (1 mark)
       2. Sea water has a lower concentration of iodide ions than the cell.
          The plant requires energy to take up the iodide ions (by active transport);(1 mark)
27.                
    1. Spiracle; (1 mark)
    2. Keep the trachea open for air passage; (1 mark)
    3.                      
       • Lacks spiral bands of chitin / to make it thin; for diffusion of gases;
       • Moist; to dissolve respiratory gases;
         (2 marks)