Biology Paper 3 Questions, Answers and Confidential - KCSE 2022 Mock Exams Set 1

Share via Whatsapp

INSTRUCTIONS TO CANDIDATES:

  1. Write your name, index number and school in the spaces provided above
  2. Sign and write the date of examination in the spaces provided above
  3. Answer all the questions in the spaces provided
  4. You are required to spend the first 15 minutes of the 1¾ hours allowed for
  5. this paper reading the whole paper carefully before commencing your work
  6. This paper has three questions
  7. Students should check the question paper to ascertain that all the papers are printed as indicated and that no questions are missing
  8. Candidates should answer the questions in English

FOR EXAMINER’S USE ONLY:

Question

Maximum

Score

Candidate’s

Score

1

14

 

2

12

 

3

14

 

Total Score

40

 

QUESTIONS

  1. You are provided with visking tubing labeled J, a piece of thread and a solution labeled K
    Dip the visking tubing in distilled water to moisten it, open it, and then tie one end tightly with the thread provided
    Half-fill the visking tubing with solution K then tie the open end of the tubing tightly Ensure solution K does not spill out of the tubing
    Immerse the visking tubing into distilled water in a beaker Ensure that the visking tubing is completely immersed in the distilled water
    Leave the set-up for 20 minutes Record your observations after 20 minutes
    1.                  
      1. Observations (1mk)
      2. Explain you observations in a (i) above (2mks)
    2. Remove the visking tubing carefully Ensure the contents of the visking tubing do not mix with that of the beakerUsing the reagents provided, test for the food substance present in the visking tubing and the beaker
      1. Visking tubing (4mks)

        FOOD TEST

        PROCEDURE

        OBSERVATIONS

        CONCLUTION

        Starch

             

        Reducing sugars

             
      2. Beaker (4mks)

        FOOD TEST

        PROCEDURE

        OBSERVATIONS

        CONCLUTION

        Starch

             

        Reducing sugars

             
    3. Explain observations in the visking tubing and Beaker in 1(b) above (3mks)
  2. The photographs I and II below illustrate parts of mammalian systems Study them and answer the questions that follow
    2 adadada
    1. Identify the two mammalian systems shown above (2mks)
    2. Name the membrane that covers part marked P and Z (2mks)
      P
      Z
    3. Describe two ways by which organ P and Z are protected (2mks)
    4. How is the part labelled Y adapted to perform its function (2mks)
    5. Identify the part labelled N (1mk)
    6. State the difference in the content of blood in L and M (1mk)

                                         L

                                        M

         
    7. State the role of the inner part of X in ensuring a healthy system (2mks)
  3. You are provided with specimens labeled S1 , S2 and S3
    1. Using a scalpel blade split S1 longitudinally and draw a well labeled diagram to show the internal structures (4mks)
    2. With a reason, state the class of the plant from which specimen S1 was obtained
      1. Class (1mk)
        Reason (1mk)
    3. Specimen S2 is a germinated seedling of S1
      In the table below, name three structures of S1 and identify the structures they developed into in specimen S2 (3mks)

      Structure in S1

       Structure developed into, in S2

      1_____________________

      2_____________________

      3_____________________

      _______________________________

      _______________________________________

      ___________________________________

    4.                                 
      1. Using specimens S2 and S3 ,name the type of germination (2mks)
        S2
        S3
      2. Give a reason for your answer in S3 above (2mks)
      3. Account for the type of germination in S2 (2mks)

CONFIDENTIAL

Each student should have;

  1. 4 test tubes and a test tube rack
  2. Iodine solution – supplied with dropper
  3. 10cm visking tubing labeled J
  4. Piece of string 20cm long
  5. 10cm3 solution of a mixture of soluble starch and glucose labeled K
    N/B. 30g glucose mixed with 3g starch then add 100cm3 water and heat to boil then cool.
  6. 500 ml beaker
  7. Adequate distilled water/ clean rain water
  8. Benedict’s solution
  9. Means of heating/ Bunsen burner
  10. Measuring cylinder – 10 ml
  11. .A scalpel.
  12. A dry bean seed labeled S1.
  13. A bean seedling labeled S2.
  14. A maize seedling labeled S3.
    Specimen S2 and S3 should be ready 1 week before the exams and must have the seeds intact.

MARKING SCHEME

  1.                              
    1.                        
      1. Visking tubing swells/ becomes turgid; (1X1 = 1mk)  
      2. High concentration of water molecules in the beaker/ distilled water compared to the visking tubing/ solution K;Water molecules move by osmosis from beaker into visking tubing; (1X2 = 2mks) 
    2.             

      I VISKING TUBING

      TEST

       

       

      PROCEDURE

       

       

      OBSERVATIONS

       

       

      CONCLUTION

      STARCH

      Put food sample in test tube add iodine solution ;

      Dark blue/ Blue black/ Black;

      Starch present;

      REDUCING SUGAR

      Put food sample in a test tube add ( equal amount of Benedict’s solution heat / warm / heat in a water bath

      For blue, green, yellow/orange/red;

      Reducing sugar present;

      II BEAKER

      STARCH

      Put food sample in a test tube add iodine solution ;

      Remain yellow brown;

      Starch absent;

      REDUCING SUGAR

      Put food sample in a test tube add (equal amount solution heat / warm/ heat in a water bath;

      Mixture turns from blue, green, yellow/ orange/red;

      Reducing sugar present;

    3.              
    4. Starch has large molecular sizes; which cannot pass through the semi-permeable visking tubing into the beaker; glucose has small molecular sizes which can diffuse across the semi-permeable visking tubing into the beaker;
  2.                              
    1. Circulatory system;
      Respiratory system;
    2. P Pericardium membrane;
      Z  Pleural membrane;
    3. by ribs; / deposits of fats to absorb shock;
    4. Rings of cartilage to keep it open 
      Ciliated epithelium to waft trapped solid particles back to the throat;
      Has goblet cells to secrete mucus to trap dust;
    5. Left atrium;/ Left auricle
    6. L Has more oxygen less CO2;  M has less oxygen;/ more carbon IV oxide
    7. has hair and mucus to trap solid particles; / warmth to incoming air;
  3.                    
    1. Magnification – 1mk.
      Each correct label-½ mk.
      Correct drawing (1mk)
    2. Class: Dicotyledonae;(1mk)
      Reason: Has two cotyledons   Accept has network veins /has at a tap root system. (1mk)
    3.                   

      Structure in S1

      Structure in S2

      Plumule

      Radicle

      Cotyledon

      Stem system /shoot

      Root system;

      Seed leaf

      3mks
    4.                            
      1. S1 – Epigeal (1mk)
      2. S3 – Hypogeal (1mk)
        The cotyledon remain below the surface of the soil. (2mks) the epicotyl elongates
      3. The cotyledon thrust above the surface of the soil; the hypocotyl elongates;

Download Biology Paper 3 Questions, Answers and Confidential - KCSE 2022 Mock Exams Set 1.


Tap Here to Download for 50/-




Why download?

  • ✔ To read offline at any time.
  • ✔ To Print at your convenience
  • ✔ Share Easily with Friends / Students


Join our whatsapp group for latest updates
.
Subscribe now

access all the content at an affordable rate
or
Buy any individual paper or notes as a pdf via MPESA
and get it sent to you via WhatsApp

 

What does our community say about us?