Biology Paper 3 Questions No Answers - Maseno Mock 2020/2021

Instructions to candidates

• You are required to spend the first 15 minutes of the 1¾ hours allowed for this paper reading the whole paper carefully before commencing your work.

1. You are provided with specimens labelled A which were soaked in water overnight
   1.  
      1. Name the part of a plant represented by the specimens (1mark)
      2. Give a reason for your answer in a) i) above (1mark)
   2. State three roles of water in germination of the specimens (3marks)
   3. Using a scalpel cut a longitudinal section of the specimen. Draw and label the section (5marks)
   4.  
      1. Name the division to which the plant from which the specimens were obtained belongs (1mark)
      2. Name the part of a flower that forms the specimen (1mark)
2. 1. Crush the cotyledons of specimen A in a mortar using a pestle into a fine paste
      

      Add enough water to make a solution.
      Use the reagents provided to test for the food substances in the solution of the cotyledons
      Record the food substances procedure, observation and conclusion in the table below.(9marks)

      Food Substance	Procedure	Observation	Conclusion

   2. Name the enzymes that would digest the food substances present in the cotyledons in the human:
      1. Mouth (1mark)
      2. Stomach (1mark)
   3. Name the by-products of the food substances in the cotyledons when digested by the
      enzymes you have stated in b above
      1. Mouth (1mark)
      2. Stomach (1mark)
3.  
   1. A response exhibited by a certain plant is illustrated in the figure below
      
      
      1. Name the type of response (1mark)
      2. Explain how the response you have named in (i) above occurs (3marks)
      3. State two survival values of the response shown by the plant in its habitat (2marks)
      4. Name the hormone and the tissue formed that lead to leaf fall (2marks)
         Hormone
         Tissue
   2. The figure below shows an organ of a certain animal
      
      
      1. Name the structure labelled X (1mark)
      2. Which cardiovascular disease may develop in part labelled Y?(1mark)
      3. State three structural differences between the interior vena cava and aorta (3marks)
      4. Name two nerves that may affect the rate at which the organ works(2marks)