Biology Paper 3 Questions - Kapsabet Boys Post Mock 2023 Exams

INSTRUCTIONS

• Answer ALL questions 
•  Candidates will be penalized for incorrect spelling especially of technical terms and for use of slovenly language
• You are required to spend the first 15 minutes of the 1¾hours allowed for this paper reading the whole paper carefully before commencing your work.

QUESTIONS

1. Study the photograph below labeled P of some animals in a certain ecosystem and answer the questions that follow.
   
   
   1.  State the type of biotic relationship shown in the photograph. (1mark)
   2.  Identify which of the two animals M and N will have the least biomass . (1 mark)
   3. Give two reasons for your answer in (b) above. (2marks)
   4. Explain the concept of “survival for the fittest” in relation to the organisms in photograph P (3marks)
   5. Explain three visible survival adaptive features for the organisms. (6marks)
2.  You are provided with iodine solution visking tubing, a beaker and a solution labelled X. Tie one end of the tubing tightly using the thread provided.
   Measure 5cm³ of solution X And pout it into t h e visking tubing. Tie the other end of the tubing tightly. Ensure there is no leakage.
   Rinse the outside of the tubing with distilled water and immerse it with its contents in a beaker containing iodine solution.
   Allow it to stand for 15 minutes.
   1.  
      1. Record your observation at the beginning and end of the experiment in the table below. (4mks)
         

         Experimental set up	Solution X inside the tubing	Iodine solution outside the tubing
         Beginning of experiment
         End of experiment

      2. What was the identity of solution X. (1mk)
      3. Suggest the nature of visking tube. (1mk) 
      4.  Account for the results obtained in a(i) above. (4mks)
   2.  
      1. Which physiological process was being investigated in this experiment? (1mk)
      2. State two factors which affect the process being investigated. (2mks)
3.  The photograph below is of a mammalian heart. Study it and answer the questions that follow
   
   
   1.  Name the parts labelled D and F. (2marks)
      D: ........................................................................................
      E: .......................................................................................
   2. State the role of part D (1mark)
   3. Account for the structural differences between the parts marked C and E. (3marks )
   4. State the function of
      1. Valve A (1mark)
      2.  Part B (1mark)
   5.  
      1. Name the part marked G. (1mark)
      2. Account for the structural differences between the parts marked G and E. (3marks)
   6.  
      1. Name the blood vessel marked M (1mark)
      2. State two defects of the circulatory system. (2marks)