Biology Paper 3 Questions and Confidential - Mumias West Pre Mock Exams 2023

INSTRUCTIONS TO CANDIDATES

• Answer ALL the questions.

FOR EXAMINERS USE ONLY

QUESTIONS

1.                      
   1. You are provided with specimen M. Peel off the epicarp. Scoop three spatulas full of the endocarp and place the portion into a clean beaker. Smash the specimen in the beaker using a glass rod. Add 20 ml of distilled water and stir using the glass rod to form solution M. Using the reagents provided carry out a food test to test for the food substance found in solution M. Spare the remaining solution to be used later. Fill the table below.
      

      Reducing sugar test	Starch test
      Observation:	Observation:
      Conclusion:	Conclusion:

      (4mks)
   2. Movement of food molecules from the digestive system into the blood stream can be investigated using avisking tube. You have been provided with a 6cm visking tube.
      
      PROCEDURE :
      Soak the visking tube in water for afew minutes then open the visking tubing and tightly tie one end such that there should be no leakage.
      Fill the tubing with 5ml of solution M from the beaker and tie the remaining end. Ensure again there is no leakage.
      Rinse the outer surface of the visking tubing to remove any traces of the paste;
      Immerse visking tubing and its contents in distilled water in a boiling tube. Pour into the boiling tube distilled water such that the visking is fully immersed.
      Leave the set up undisturbed for at least 20 minutes. Carefully remove the visking tubing and its contents from the boiling tube.
      After 20 minutes carry out afood test again using the sample of water from the boiling tube in which the visking tube had been immersed.
      

      Reducing sugar test	Starch test
      Observation:	Observation:
      Conclusion:	Conclusion:

      (4mks)
   3.                    
      1. Why was the visking tube rinsed before the start of the experiment. (1mk)
      2. Explain what has happened in (b) above at the end of the experiment. (2mks)
   4. Name the part of the digestive system that might be represented by the visking tube. (1mk)
   5.                    
      1. Name the blood vessel that transports oxygenated blood from the part named (d) above to organ R(in question 2 below). (1mk)
      2. With reference to the visking tube provided state one observable feature that adapts the part named in (d) above to its function. (1mk)
2. You are provided with a photograph of specimen R showing an organ from the body. You are also provided with a piece of specimen R. Study them and answer the questions that follow.
   
   
   1.                        
      1. Name specimen R. (1mk)
      2. label on the photograph the following parts. (3mks)
         • Gall bladder
         • Aorta.
         • Inferior venacava
   2. Explain why malfunctioning of R leads impaired sugar regulation. (3mks)
   3. Cut specimen R into two equal pieces. Immerse one piece into aboilling tube. Add alittle water and boil it for five minutes. Label one boiling tube A. Label another boiling tube B. Using a pair of forceps remove the piece of R that has been boiled from the boiling tube and put it in the boiling tube labeled A. Take the remaining piece of R that was not boiled and put it into the other boiling tube labeled B. In each of the boiling tubes A and B add 10 ml of hydrogen peroxide respectively.
      1. Record your observation
         A: (1mk)
         
         B: (1mk)
      2. Account for the observation in
         A: (2mks)
         
         B: (1mks)
      3. Which excretory function of specimen R is being investicated. (1mk)
      4. State one disease that can affect specimen R. (1mk)
3. You are provided with specimens H and K. Observe the specimens keenly.
   1. State two functions of specimen K. (2 marks)
   2. Name the division and class to which specimen H belongs.
      Division  (1 mark)
      
      Reason  (1 mark)
      
      Class  (1 mark)
      
      Reasons (2 marks)
   3. State three adaptations of specimen K for maximum photosynthesis. (3marks)
   4. Explain two ways in which specimen H is adapted for survival in its habitat. (2 marks)

CONFIDENTIAL

Each candidate will require the following;

1. Empty 100ml/250ml beaker/test tube rag
2. Distilled water
3. 4 boiling tubes
4. 10ml measuring cylinder
5. Stopwatch
6. Scalpel
7. Glass rod
8. 50ml plastic beaker
9. Spatula
10. Dropper
11. 4 test tubes
12. Specimen R - Asmall piece of liver
13. Specimen H - complete grass
14. Specimen K - Bipinnate leaf
15. Specimen M - Half portion of ripe banana
16. 8cm visking tube
17. 2 pieces of thread
18. Two labels

Access to:

1. Source of heat
2. Benedict’s solution
3. Iodine solution NOTE: 

   THE PHOTOGRAPH SHOULD COLOURED