KCSE BIOLOGY PAPER 1 2020

 KCSE 2010 BIOLOGY PAPER 1

 

1. State the name given to the study of :

(a) The cell

• Cytology

(b) micro-organisms

•  Microbiology

2. The diagram below show a transverse section of a plant organ.

 

 

 

(a) Name the plant organ from which the section was obtained

• Stem

 (b) (i) Name the class to which the plant was obtained (1mk)

• Monocotyledonae

      (ii) Give the reason for your answer in b(i) above        (1mk)

• Vascular bundles are scattered

(c) Name the part labelled X                      (1mk)

• Epidermis

 3. State the function of:

 (a) Ribosomes                                         (1mk)

• Protein synthesis
  

 (b) Lysosomes                                         (1mk)

• Destroys worn out organelles

4.The diagram below shows a specialized plant cell

 

(a) (i) Name the cell.

• Root hair cell

    (ii) Name the parts labeled D and E.

• D-cell wall 
• E-cell sap(Vacuole)

   (iii) State the function of the part labelled C

• Controls cell activities

5. . State three ways in which a respiratory surface is adapted to its function. 

•  It has a large surface area for efficient diffusion of gases
• Moist to dissolve gases before diffusion
• This for efficient diffusion of gases across a short distance
• Highly vascularized to transport diffused gases efficienty
  

6. State one function for each of the following: 

(a) Cerebellum   

• Maintain balance   

(b) Medulla oblongata  

• controls heart beat 

 7. Distinguish between haemolysis and plasmolysis.    

• Hymolysis :process by which red blood cell take in water until they burst
• Plasmolysis: loss of water from plant cell until the membrane is detached from the cell wall
  

8. State three external differences between chilopoda and diplopoda.   

•  chilopoda has a pair of walking legs per segment while diplopoda has two pair of walking legs per segment
• chilopoda has dosoventrally flattened body while diplopoda has cylindrical body
• chilopoda's body is divided into head and trunk while diplopoda's body is divided into head thorax and trunk
• chilopoda has posterior genital aperture while diplopoda has anterior genital aperture
• chilopoda has poisonous claws while diplopoda lacks poisonous claws
  

 9. State two ways in which chloroplasts are adapted to their function.  

• contains chlorophyll which absorbs light energy
• It has stroma which contains enzymes for photosynthesis
• It has a large number of grana which increases surface area for accommodation of a large number of chlorophyll molecules for photosynthesis

 10. State two advantages of hybrid vigour.     

• resistance to diseases
• early maturity
• Increased yields
• resistance to drought
  

 11. The diagram below shows a transverse section of a leaf.