Biology Paper 1 Questions and Answers - Form 3 Mid Term 2 Exams 2021

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  • Answer ALL questions.
  1. Using definition only differentiate between growth and development  (2 mks)
  2. Name two cell structures that synthesize the following cell organelles (2 mks)
    1. Ribosomes
    2. Nucleolus
  3. Give four different between plants and animals (4 mks)
  4. Give the functions of the following parts of a microscope (4 mks)
    1. Condenser
    2. Objective lens
    3. Body tube
    4. Diaphragm
  5. Study the reaction below and answer the questions that follow.
             F3 MT2 Bio PP1 Q5 2021
    1. What biological processes are represented by A and B? (2mk)
    2. Identify the product Y. (1mk)
    3. State the bond represented by X. (1mk)
  6. In an experiment to investigate an aspect of digestion, two tubes A and B were set up as shown in the diagram below.
    F3 MT2 Bio PP1 Q6 2021
    The test tubes were left in the water bath for 30 minutes. The content of each tube was then tested for starch using iodine solution.
    1. What was the aim of the experiment?  (1 mk)
    2. Explain the expected in the tube.  (4 mks)
  7. Explain the events of the light stage of photosynthesis. (3mk)
  8. State two adaptations of red blood cells to their functions (4 mks)
  9. Explain how the following adaptation reduce transpiration in xerophytes a
    1. Sunken stomata (2 mks)
    2. Thick waxy cuticle (2 mks)
  10. Name the:
    1. Material that strengthens xylem tissue (1 mk)
    2. Tissue that is removed when the bark of a dicotyledonous plant is ringed (1 mk)
    3. Conducts water in a plant (1 mk)
  11. The diagram below represents an organ from a bony fish. Study the diagram and answer the questions that follow:
             F3 MT2 Bio PP1 Q11 2021
    1. State the functions of each of the following: (3 mks)
    2. How is the structure labeled C adapted to its function (4 mks)
    3. Name one part of the mammal that the above organ represents in function (1 mk)
    1. Give two phases of aerobic respiration (2mks)
    2. Give two end products anaerobic respiration  (2 mks)
  13. Name three plant leaf excretory products  (3 mks)
  14. A student mixed a sample of urine from a person with Benedict's solution and heated, the colour changed to orange
    1. What was present in the urine sample  (1 mk)
    2. What did the student conclude on the health status of the person (2 mks)
    3. Which organ in the person may not be functioning properly (1 mk)
  15. Name three diseases that affect the kidney (3mks)
    1. What is meant by the term taxonomy (1 mk)
    2. The scientific name of a rat is Rattusnorvegicus
      1. Write the name correctly (1 mk)
      2. Identify the genus and species names  (2mks)
  17. The diagram below represents a bread mould:
             F3 MT2 Bio PP1 Q17 2021
    1. Identify the kingdom to which the organism belongs (1 mk)
    2. Name the part marked R  (1 mk)
    3. Identify three types of leaf phylotaxy(3 mks)
  18. What is the significance of the following in the ecosystem:
    1. Decomposers (2 mks)
    2. Predators   (2 mks)
  19. Birds feed on grasshoppers that feed on grass.
    1. Draw a possible food chain from the above information  (2 mks)
    2. Explain why the biomass of organisms decreases at each preceding trophic level
      (2 mks)
  20. Name the causative agent of the following diseases,
    1. Cholera  (1 mk)
    2. Typhoid    (1 mk)
  21. Identify three ways of estimating population size in a population (3mks)
  22. Name two part of an ovule that develops into each of the following parts of a seed after fertilization   (2 mks)
    1. Testa
    2. Endosperm


  1. Growth is the irreversible increase in size and mass while development is the irreversible change in complexity of a living organism. (1x2 = 2mks)
    Award as a whole
    1. Nucleolus (1x1 = 1mk)
    2. Nucleus (1x1 = 1mk)
  3.          Plants                                                Animals
    • Have chlorophyll                                 No chlorophyll
    • Have cellulose cell wall                        Lack cellulose cell wall
    • Respond slowly to changes                  Respond quickly
      in their environment
    • Plants do not move about                    Do move about
    • Lack specialized excretory organs         Have complex excretory organs
      (1x4 = 4mks)
    1. Concentrates light on the object on the stage (1x1 = 1mk)
    2. Brings image into focus and magnifies it (1x1 = 1mk)
    3. Holds the eye-piece and revolving nose-piece (1x1 = 1mk)
    4. An aperture that regulates the amount of light passing through the condenser to illuminate the specimen (1x1 = 1mk)
    1. A - Condensation
      B –Hydrolysis (1x2 = 2mks)
    2. Sucrose (1x1 = 1mk)
    3. Covalent bond (1x1 = 1mk)
    1. To investigate the effect of boiled saliva on starch/to show the effect boiled/denature enzyme amylase has on starch; (1x1 = 1mk)
      • A-brown colour/colourof iodine persists;
        B- blue black/blue/dark colouration;
      • A-starch has been digested/starch has been broken down/amylase hydrolyses starch hence no colour changes;
        B-enzymes/amylase denatured hence no starch digested; (1x4 = 4mks)
    • Oxygen-releases to the atmosphere or used by plants for respiration;
    • Hydrogen-enter dark stage, where it combines with CO2 to form simple sugar;
    • ATP- provide energy during the combination of hydrogen a toms with CO2in dark stage;
    • Biconcave disc shaped to increase surface area for gaseous exchange;
    • Have no nucleus to increase room for the package of red blood cells;
    • Numerous in number to increase surface area for the transportation of oxygen
    • Have haemoglobin which has a high affinity of oxygen;
    • Cytoplasmic filaments/strands along which food streams;
    • Companion cells have mitochondria that provide energy for translocation;
    • Sieve plates with sieve pores through which cytoplasmic filaments pass.
    • Photoplasmic material pushed on the sides to create lumen space for translocation;
    1. Sunken stomata form pits; in which water vapour accumulates reducing rate of transpiration    (1x2= 2mks)
    2. Water proof; to reduce the rate of transpiration; (1x2 = 2mks)
    1. Lignin; (1x1 = 1mk)
    2. Phloem; (1x1 = 1mk)
    3. Xylem; (1x1 = 1mk)
    1. A – Gill rakers act as a screen preventing entry of food and other particles that might damage the delicate gill lamella; (1x1 = 1mk)
      B – Gill bar for attachment of gill rakers and gill filament (1x1 = 1mk)
      C – Gill filaments – the surface on which gaseous exchange take place (1x1 = 1mk)
    2. Filaments are supplied with a dense network of blood capillaries for the efficient transportof gases;
    3. Lungs (1x1 = 1mk)
      • Glycolysis
      • Krebs cycle
        (1x2 = 2mks)
      • Carbon IV Oxide
      • Ethanol
      • Energy
        (1x2 = 2mks)
    • Carbon dioxide
    • excess water
    • nitrogenous compounds
      (1x3 = 3mks)
    1. Glucose; (1x1 = 1mk)
    2. The person was a sufferer of diabetes mellitus; (1x1 = 1mk)
    3. Pancreas; (1x1 = 1mk)
    • Nephritis
    • Kidney stone
    • Albuminuria
    • Kidney failure
      (1x3 = 3mks)
    1. taxonomy is the classification of living organisms on their similarities and difference observed
      (1x1= 1mk)
      1. Rottusnorvegicus (1mk) (Genus name MUST begin with capital letter and be underlined separately) (1x1 = 1mk)
        • Genus – Rattus;
        • Species – norvegicus; (1x2 = 2mks)
    1. Fungi; (1x1 = 1mk)
    2. Sporulation; (1x1 = 1mk)
      • Wholed
      • Opposite
      • Alternate
        (1x3 = 3mks)
    1. Help to breakdown dead organic matter hence reducing bulk; in the recycling of Nutrients;
    2. Regulate the predator – prey population; (1x2 = 2mks)
    1. Grass→Grasshoppers → Birds; (1x2 = 2mks)
    2. Not all the energy is transferred from one trophic level to another; some is lost as heat, some is used up during metabolism and some is lost when organisms die and decay; (1x2 = 2mks)
    1. Vibriocholerae (1x1 = 1mk)
    2. Salmonelatyphe (1x1 = 1mk)
    1. Quadrat
    2. Capture Recapture method
    3. Line transect
    4. Belt transect
      (1x3 = 3mks)
    1. Integuments ; (1x1 = 1mk)
    2. Primary endosperm nucleus; (1x1 = 1mk)

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