KCSE 2011 Biology Paper 3 Questions with Marking Scheme

Share via Whatsapp
Download PDF for future reference Get on Whatsapp for 50/-
  1. Below is a diagram of a fish. Examine it and answer the questions that follow.

    photo of fish kcse 11

    1. Name the parts labeled K, L, M and N. (4 marks)

    2. The actual length of the pair of scissors next to the fish is 12.5cm. Using this information, calculate the actual length of the fish. (3 marks)

    3. Name the fins that prevent the following movements of fish during swimming. (3 marks)
      1. Yawing
      2. Pitching; 

    4. The photograph below shows visible structures after removing the part labeled P.
      The inset is a magnified view of one of the structures.

      fish fins kcse 11

      1. Name the parts labeled R, S and T. (3 marks)

      2. Explain how each of the following parts named in (d) (i) above is adapted to its function. (3 marks)

  2. The photographs labeled D and E shows two types of leaves.

    dicotyledonous leaf kcse 11

    monocotyledonous leaf kcse 11

    1. With a reason, state the classes of plants from which the leaves in photographs D and E were obtained. (4 marks)

    2. State three features in the leaf shown in photograph D that adapt it to its functions. (3 marks)

    3. The photographs below show the structures observed in cross sections of parts of two types of plants as seen under a light microscope.

      light microscope kcse 11

      1. Name the parts labeled U,V and W. (3 marks)

      2. Identify five differences between cross sections F and G. (5 marks)


  3. You are provided with a food sample X in solution form, solution J (Iodine solution), solution K (Benedict’s) and solution L (Biuret’s reagent). Carry out tests on the food sample to identify the type of food substances present. (9 marks)

    Food being tested for Procedure Observations Conclusion
           
           
           

MARKING SCHEME

  1.      
    1. K - Pectoral fin
      L - Dorsal fin
      M - Anal fin
      N - Pelvic fin
    2. The size of scissors on the photograph is 4.6
      The length of fish on the photograph is 13.6 };
      Mg = Image length
               Actual length
      Actual length of fish is 13.6 X 12.5  = 36.96 cm;
                                            4.6
    3.    
      1. Yawing - Dorsal fin;
      2. Pitching - Pectoral fin; Pelvic fin;
    4.          
      1. R - gill rakers
        S - gill bar
        T - gill filaments

      2. r - sharp/numerous/pointed/arranged closely in a row to trap solids that can damage the filaments;
        S - rigid/firm to hold gill filaments in place;
        T -  numerous to increase surface area for gaseous exchange/thin to reduce the distance for gaseous exchange/vascularized to transport respiratory gases away from the respiratory surface moist to dissolve oxygen for diffusion;
  2.          
    1. Leaf D - class dicotyledonae;
      Reason - network of veins/presence of petiole;
      Leaf E - class monocotyledonae;
      Reason - parallel venation/presence of leaf sheath;
    2. Broad and flat to offer a large surface area for photosynthesis;
      Thin to reduce distance over which carbon IV oxide diffuses to reach the mesophyll cells;
      Rich supply of veins to transport water to photosynthetic cells;
      Presence of chlorophyll to absorb light for photosynthesis;
    3.      
      1. U - xylem;
        V - phloem;
        W - cambium;
      2.      
         
        Cross section of F Cross section of G
        No pith
        Vascular bundles scattered
        Vascular bundles numerous
        Cambium absent
        Cortex absent
        Small vascular bundles
        pith present;
        vascular bundles in a ring;
        vascular bundles few;
        cambium present;
        cortex present;
        large vascular bundles;
            (Total = 15 marks)
  3.      
    PROCEDURE OBSERVATION CONCLUSION
    Iodine solution/solution J
    (added to the food sample drop by drop while shaking) 
    Blue black colour formed; Starch present in food sample;
    Benedict's solution/ solution K added to the food sample
    in test tube in equal amounts.
    The test tube is then placed in a hot water bath
    Solution changes colour to green,yellow
    and  then orange/brown
    More reducing sugar present in food sample
    Biuret's reagent/solution L added to the food sample
    drop by drop while shak ing; 
    Colour of reagent retained Protein absent in the food sample;
    Award marks for correct procedure, observation and conclusion only.
    (9 marks)

Download KCSE 2011 Biology Paper 3 Questions with Marking Scheme.


Tap Here to Download for 50/-





Join our whatsapp group for latest updates
Read 2526 times Last modified on Wednesday, 10 November 2021 11:39
Print PDF for future reference