Biology Paper 3 Questions - Maseno Mock Examinations 2022

QUESTIONS

1. You are provided with two pieces of plant material labeled T. Using a surgical blade, cut a slit a half way through the middle piece as shown below.
   
   Place one piece in liquid labeled R and the other in liquid labeled S. Allow the set up to stand for 30 minutes.
   1. State the observation made in the piece placed in;
      1. Liquid R (1 mark)
      2. Liquid S (1 mark)
   2. Account for the observations stated in (a) above
      1. Piece place in liquid R (3 marks)
      2. Piece placed in liquid S (3 marks)
   3. Describe the nature of liquid R and S in relation to the cell sap of pieces used in the experiment
      1. R (1 mark)
      2. S (1 mark)
   4. Name the chemical substances present in the cell structure responsible for the above physiological process (2 marks)
   5. Describe how the cell structure works to bring about the observations made in (a) above. (2 marks)
2. The photograph below represents part of human skeleton
   
   
   1. Name three bones that fuse to form the part labeled C (3 marks)
   2. Explain the significance of part G (3 marks)
   3. State the function of part Q (1 mark )
   4. Name three structures that pass through the part labeled W (3 marks)
   5.    
      1. Name the type of joint found between the bones named in (a) (1 mark)
      2. Explain the significance of joint identified in e (i) above (1 mark)
3. You are provided with solution Q.
   1. Place two drops of solution Q on a white tile and two drops of iodine solution onto it. Make your observation and tabulate your results in the table below. (3 marks)
      

      Food substance	Observation	Conclusion

   2. Measure about 2.0ml of solution Q and transfer into a clean test tube, add equal amount of Benedicts solution and heat the mixture to boil in a water bath maintained at 37ºC. Tabulate your results in the table below. (3 marks)
      

      Food substance	Observation	Conclusion

   3. Label two test tubes B1 and B2. Add 2ml of liquid Q followed by 2ml of liquid T. to the content of B1, add 2ml of HCl and to content of B2, add 2ml of NaHCO₃ solution. Place the two test tubes in a water bath maintained at 37ºC for 20 minutes. Remove the test tubes from the water bath and allow to cool.
      To the content of each test tube, add 2ml of Benedicts solution and heat to boil in the water bath. Tabulate your results in the table below (4 marks)
      

      Test tube	Observation	Conclusion
      B1
      B2

   4.     
      1. Name the likely identity of liquid T (1 mark)
      2. Explain your answer in d (i) above (1 mark)
   5. Name two secretions that create an optimum conditions for T along the alimentary canal. (2 marks)