Biology Paper 1 Questions and Answers - Pavement Pre-Mock Exams 2021/2022

Instructions To Candidates 

• Answer ALL the questions.
• Answers must be written in English only.

1.  
   1. What is meant by the term binomial nomenclature? (1mark)
   2. Give two reasons why classification is important (2 marks)
2.  
   1. What is the formula for calculating linear magnification of a specimen when using a hand lens? (1mark)
   2. Give a reason why staining is necessary when preparing specimens for observation under the microscope
      (1 mark)
3. Plant cells do not burst when immersed in distilled water. Explain (2marks)
4. State three functions of Golgi apparatus. (3 marks)
5. Distinguish between diffusion and osmosis. (2 marks)
6. Describe what happens during the light stage of photosynthesis. (3 marks)
7. The diagram below represents a section though a human tooth
   
   1.  
      1. Name the type of tooth shown (1 mark)
      2. Give a reason for your answer in (a) (i) above (1 mark)
   2. State the functions of the structures found in part labeled J (2 marks)
8.  
   1. Name a fat soluble vitamin manufactured by the human body. (1 mark)
   2. State two functions of potassium in the human body . (2 marks)
9. State two ways in which the root hairs are adapted to their function. (2 marks)
10.  
    1. State the functions of cristae in mitochondria. (1mark)
    2. The diagram below represents a cell organelle.
       
       1. Name the part labeled Y. (1mark)
       2. State the functions of the part labeled X. (1mark)
11. Name the part of the flower that develops into (2marks)
    1. Seed………………………………………………………………………………………………………
    2. Fruit………………………………………………………………………………………………………
12.  
    1. Name the fluid that is produced by sebaceous glands. (1mark)
    2. What is the role of sweat in human skin? (2marks)
13. State two ways in which floating leaves of aquatic plants are adapted to gaseous exchange.    (2marks)
14.  
    1. State three characteristics of Monera that are not found in other kingdoms. (3marks)
    2. Name the class to which a termite belongs (1mark)
15.  
    1. Name one defect of circulatory system in humans. (1mark)
    2. State three functions of blood other than transport. (3marks)
16. State the role of vitamin C in humans. (1mark)
17.  
    1. State two processes which occur during anaphase of mitosis. (2marks)
    2. What is significance of meiosis? (2marks)
18. State the role of insulin in human body. (1marks)
19. An experiment was set up in the experiment as show below.
    
    The set up was left for 30 minutess.
    1. State the expected results. (1mark)
    2. Explain your answer in (a) above (3marks)
20.  
    1. In what form is energy stored in muscles (1mark)
    2. State the economic importance of anaerobic respiration in plants. (2marks)
21.  
    1. Distinguish between epigeal and hypogeal germination. (2marks)
    2. Why is oxygen necessary in the germination of seeds? (2marks)
22.  
    1. What prevents blood in veins from flowing backwards? (1 mark)
    2. State two ways in which the red blood cells are adapted to their function (2 marks)
23. What is the importance of the following in an ecosystem? (2marks)
    1. Decomposers
    2. Predation
24.  
    1. Distinguish between the terms homodont and heterodont. (1mark)
    2. What is the function of carnassials teeth? (1mark)
    3. A certain animal has no incisors, no canines, 6 premolars and 6 Molars in its upper jaw. In the lower jaw there are 6 incisors, 2 canines, 6Premolars and six molars. Write its dental formula. (2marks)
25.  
    1. State two functions of bile juice in the digestion of food. (2marks)
    2. How does substrate concentration affect the rate of enzyme action? (1mark)
26.  
    1. Explain how the following prevent self-pollination. (2marks)
       1. Protandry
       2. Self – sterility.
    2. Give three advantages of cross pollination. (3marks)
27. State four ways in which respiratory surfaces are suited to their function. (4marks)

MARKING SCHEME

1.  
   1. What is meant by the term binomial nomenclature? (1mark)
      
      • Double naming system of living organisms.
   2. Give two reasons why classification is important (2 marks)
      • Bring together living organisms with similar characteristics; separate those with different features.
        
      • Places organisms into their groups for reference
        
      • To avoid and confusion
2.  
   1. What is the formula for calculating linear magnification of a specimen when using a hand lens?(1mark)
      Magnification = length of the drawing
                                       Actual length
   2. Give a reason why staining is necessary when preparing specimens for observation under the microscope
      (1 mark)
      
      • For easy visibility/ for clarity/increases clarity
3. Plant cells do not burst when immersed in distilled water. Explain (2marks)
   
   • Cell wall cellulose; its firm
4. State three functions of Golgi apparatus. (3 marks)
   
   • Package and transport glycoprotein as secretions.
     
   • Transport synthesized materials out of the cell
     
   • Forms enzymes and secretion of synthesized proteins and carbohydrates
5. Distinguish between diffusion and osmosis. (2 marks)
   
   • Diffusion; movement of molecules from a region of high concentration to a region of low concentration
     
   • Osmosis; movement of water molecules from a high water potential to a low water potential across a semi permeable membrane
6. Describe what happens during the light stage of photosynthesis. (3 marks)
   • Water molecule is split into hydrogen atoms and oxygen atoms; a process called photolysis; hydrogen ions goes to the dark stage; oxygen gets out as a by product
7. The diagram below represents a section though a human tooth
   1.  
      1. Name the type of tooth shown ( 1 mark)
         • Molar/premolar
      2. Give a reason for your answer in (a) (i) above (1 mark)
         • Presence of multiple roots
         • Presence of cusps
   2. State the functions of the structures found in part labeled J (2 marks)
      • Detect heat, cold and pain
8.  
   1. Name a fat soluble vitamin manufactured by the human body. ( 1 mark)
      • Vitamin D
   2. State two functions of potassium in the human body . (2 marks)
      • Transmission of nerve impulses
9. State two ways in which the root hairs are adapted to their function. (2 marks)
   • Small in size; to increase surface area for absorption of water and mineral salts
   • Presence of sap; to increase the osmotic pressure
10.  
    1. State the functions of cristae in mitochondria.(1mark)
       • Increase surface area for the attachment of respiratory enzymes
    2. The diagram below represents a cell organelle.
       1. Name the part labeled Y. (1mk)
          • Stoma
       2. State the functions of the part labeled X. (1mk)
          • Light stage of photosynthesis occurs here
11. Name the part of the flower that develops into(2mks)
    1. Seed - ovules
    2. Fruit - ovary
12.  
    1. Name the fluid that is produced by sebaceous glands. (1mk)
       • Sebum
    2. What is the role of sweat in human skin? (2mks)
       • Excretion
       • Temperature regulation
13. State two ways in which floating leaves of aquatic plants are adapted to gaseous exchange.(2mks)
    • numerous stomata on the upper leaf surface
    • Thin cuticle
14.  
    1. State three characteristics of Monera that are not found in other kingdoms. (3mks)
       • Have cell wall made of Murein
       • Genetic/ nuclear material not surrounded by a nuclear membrane hence prokaryotic
       • Lack most organelle/have few organelles/mitochondria absent.
    2. Name the class to which a termite belongs (1mk)
       • insecta
15.  
    1. Name one defect of circulatory system in humans. (1mk)
       • Arteriosclerosis; varicose vein
    2. State three functions of blood other than transport. (3mks)
       • Regulation of pH
       • Regulation of body temperature
       • Blood clotting
16. State the role of vitamin C in humans. (1mk)
    • Protection against infection
    • Collagen synthesis for bone cartilage and gums
    • An antioxidant and aids in detoxification
17.  
    1. State two processes which occur during anaphase of mitosis. (2mks)
       • Chromatids separate at the centromere and migrate to the opposite poles
       • Spindle apparatus begin to disappear
    2. What is significance of meiosis? (2mks)
       • leads to variation; formation of gametes
18. State the role of insulin in human body. (1mks)
    • Stimulate liver cells to convert excess glucose to glycogen for storage
19. An experiment was set up in the experiment as show below.The set up was left for 30 minutes.
    1. State the expected results. (1mk)
       • visking tubing increased in size;
    2. Explain your answer in (a) above (3mks)
       • Sucrose in the visking tubing was hypertonic; water from the beaker entered the visking tubing by osmosis; increasing in size
20.  
    1. In what form is energy stored in muscles (1mk)
       • Glycogen
    2. State the economic importance of anaerobic respiration in plants. (2mks)
       • Bread making; brewing of beer; making of silage
21.  
    1. Distinguish between epigeal and hypogeal germination. (2mks
       • Epigeal; cotyledons come out of the soil
       • Hypogeal; cotyledons remain underground
    2. Why is oxygen necessary in the germination of seeds? (2mks)
       • For respiration
22.  
    1. What prevents blood in veins from flowing backwards? (1 mark)
       • Valves
    2. State two ways in which the red blood cells are adapted to their function (2 marks)
       • Presence of haemoglobin that have high affinity for oxygen and carbon (IV) oxide;
       • Thin membrane for easy diffusion of respiratory gases
       • Biconcave to increase SA for transportation of oxygen and carbon (IV) oxide
       • Small in size to squeeze in the small capillary wall
23. What is the importance of the following in an ecosystem? (2mks)
    1. Decomposers
       • recycling of nutrients
    2. Predation
       • Check on the population of preys and predators
24.  
    1. Distinguish between the terms homodont and heterodont. (1mk)
       • Homodont; teeth uniform in size and shape
       • Heterodont;teeth different in size and shape
    2. What is the function of carnassials teeth? (1mk)
       • Breaking bones and tearing through flesh
    3. A certain animal has no incisors, no canines, 6 premolars and 6 Molars in its upper jaw. In the lower jaw there are 6 incisors, 2 canines, 6Premolars and six molars. Write its dental formula.(2mks)
       i⁰/₃;c⁰/₁;pm³/₃;m³/₃ = 32
25.  
    1. State two functions of bile juice in the digestion of food. (2mks)
       • Emulsification
       • Neutralizes chyme
    2. How does substrate concentration affect the rate of enzyme action?(1mk)
       • Increase in substrate concentration increases rate of enzyme concentration
26.  
    1. Explain how the following prevent self-pollination. (2mks)
       1. Protandry stamen mature earlier than pistil and falls off
       2. Self – sterility. When the male and female gametes of the of the same flower are not compatible
    2. Give three advantages of cross pollination. (3mks)
       • leads to hybrid vigour/ heterosis
       • Increases variety;
         
       • Resistance of disease/ drought/ dry climate/ unfavorable environmental conditions/ Frost; E.g. resistance to virus, fungi, bacterial diseases of pest.
27. State four ways in which respiratory surfaces are suited to their function. (4mks)
    • They are moist
    • Thin membrane
    • Highly vascularized
    • Numerous