Biology Paper 1 Questions and Answers - Form 3 End Term 2 Exams 2023

QUESTIONS

1. The scientific name of the cat is Felis Catus classify the cat  into; (3mks)
   1. Kingdom………………………………………
   2. Genus…………………………………………
   3. Species………………………………………
2. The figure below shows a structure of a tooth:
          
   1. Identify the tooth: - (1 mk)
   2. State how the tooth named in (a) is modified to perform its function:- (1 mk)
3.  
   1. Name the hormone secreted in the human body when one takes in a large amount of  water:- (1 mk)
   2. Which disease results from inadequate production of the hormone named in (a) above?  (1mk)
4. Give two structural features that can be used to separate a housefly, a millipede, and a tick into their respective classes. (2mks)
5. State three main functions of the stomach in human beings:- (3 mks)
6. It was found that during germination of bean seeds, 9.2cm³ of carbon IV Oxide was produced while 9.0cm³ of oxygen was used up.
   1.  
      1. the respiratory quotient of the reaction:- (2 mks)
      2. Identify the substrate being met abolished:- (1 mk)
   2. In which part of the cell does glycolysis occur? (1 mk)
7. State three functions of the mammalian blood other than transport (3mks)
8. Other than sexual intercourse name the other ways by which HIV/AIDS is spread (3mks)
9. State three characteristics features of an efficient respiratory surface (3mks)
10. State three environmental factors that affect the rate of stomatal transpiration (3mks)
11. The cells shown below are adapted for transport in flowering plants.
            
    1. Name the tissue in which these cells are found. (1 mk)
    2. Identify and explain two observable features of these cells that adapt them to their role in transport. (2mks)
12. Name two areas in human body where active transport takes place. (2mks)
13. State the functions of the following cell organelles:    (2mks)                                                                 
    1. Nucleolus.
    2. Plasma membrane
14. Distinguish between guttation and transpiration (2mks)
15. What are the functions of the following parts of a light microscope? (3mks) 
    1.  Eye piece lens
    2. Condenser
    3. Diaphragm
16.  
    1. What is peristalsis? (1mks)
    2. Explain how the process above is brought about. (2mks)
17.  
    1. State three structural differences between arteries and veins in mammals (3mks)
    2. Name a disease that causes thickening and hardening of arteries (1mk)
18. Identify two forces that help in upward movement of water in plants (2mks)
19. State two reasons why lipids are rarely used as a respiratory substrate compound to Carbohydrates.  (2mks)
20. The equation below represents a metabolic process that occurs in the mammalian liver:  (2mks)         
    Amino acids   →    organic compound + urea 
    1. Name the process
    2. What is the importance of the process to the mammals?
21.  
    1. Define the term balanced diet.                 (2mks)
    2. State the importance of roughage in a diet.       (1mark)
22. How do the following factors affect the rate of diffusion? (3marks)
    1. Surface area to volume ratio
    2. Diffusion gradient
    3. Temperature
23. Name any three specialized plant cells. (3marks)
24. Name three sites where gaseous exchange takes place in terrestrial plants. (3 marks)
25. A student in form three caught an organism which had the following characteristics
    1. Body divided into two parts.
    2. Simple eyes.
    3. Eight legs.
       Classify the organism up to the class level. (3 marks)
26.  
    1. Distinguish between the counter flow and parallel flow system in gaseous exchange(1mk)
    2. Which of the two systems mentioned in (a) above is efficient? Give a reason (2mks)
27. Name the enzyme, the vitamin and the metallic ions required in the clotting of blood. (3mks)
    1. Enzyme
    2. Vitamin
    3. Metallic ion
28. The figure below is a photomicrograph of a section of mammalian skin. Study it and answer the questions that follow. 
           
    1. State two functions of the secretion frm the gland labeled C (2marks)
    2. Explain the behaviour of structure E when environmental temperature falls to 100c. (2marks)
29. Astronauts from the outer space brought a material to earth. Explain how you would establish if the material is living or non-living. (2marks)

MARKING SCHEME

1.  
   1. animalia
   2. felis
   3. catus
2.  
   1. Incisor tooth (2 mks)
   2. Chisel shaped for cutting;
3.  
   1. Anti diuretic hormone / Vasopressin
   2. Diabetis insipidus
4.  
   • Number of body parts.
   • Number of legs
5.  
   1. Temporary storage of food
   2. Secretes digestive enzyme
   3. Secretes mucus                          -   gastric juice
   4. Secretes Hcl   -   Endocrine function i.e.  Gastrine hormone
6.  
   1.  
      1. RQ = CO₂ Produced
                     O₂ Produced
                = 9.2
                    9
                 = 1
      2. Carbohydrates
   2. Cytoplasm-Regulation of body temperature
7.  
   • Regulation of body p
   • Defence through white blood cells
   • prevents excessive bleeding platelets
   • Allows the dehiate underlying tissues heal rapidly.
8.  
   • sharing of sharp objects with infected perform
   • blood transfusion of infected blood
   • infected mother to child (breast feeding)
9.  
   • Thin walls
   • a moist inner surface
   • a large combined surface area
   • and a rich blood supply
10.  
    • light
    • temperature
    • wind
    • Atmospheric pressure
    • humidity
11.  
    1. Xylem;
    2.  
       • Cross walls between successive vessel elements are performed, giving free passage of water from cell to cell;
       • There is dissolution of cross walls within the vessel elements thus forming      an open tube along the axis of the organ;
       • Thick (cellulose ) / lignified wall / rings prevents collaps  (under tention;
       • Lack of long contents / hollow / empty allows free flow
       • Wide lumen / cavity to ease flow / large volume;
       • Stacked end to end / elongated forming a continuous tube. -                                               
12.  
    • Small intestines (in absorption of digested food)
    • Kidney (in selective re – absorption
13.  
    1. Manufacture of ribosomes;
    2. encloses cell contents; regulate movement of materials in and out of the cell;
14. Transpiration is the loss of water vapour, while gutation is loss or exudation of liquid water through hydathodes
15.  
    • Magnify the object further;
    • Concentrates light onto the object;
    • Controls amount of light illuminating the object;
16.  
    1. Involuntary movement of food along the alimentary canal 
    2. Rhythmic contraction and relaxation of the circular and longitudinal muscles along the gut;
17.  
    1.   
       

       Arteries	Veins
       - Thick muscular - No valves (except pulmonary artery and aorta at the base - Narrow (small) lumen	- Thin muscular walls - valves present; - Wide lumen (large) lumen;

    2. Arteriosclerosis; reject Artheroma
18.  
    • Transpiration pull; Capillarity;
    • Cohesion and adhesive forces; Root pressure; -
19.  
    • Not every soluble/not readily soluble therefore not easily transported to the site of respiration;
    • A lot of oxygen is required to oxidize one gram of fat/liquid than one gram of glucose;
20.  
    1. Deamination;
    2.  
       • Removal of excess amino acids;
       • Availing  of  energy in  the  body;
       • Formation of  glycogen /fats  for storage; (award any one)
21. 1. Is a diet that consists of all classes of food / carbohydrates, protein, lipids, water, mineral salts and  vitamins; taken in their right proportions for a healthy body;                      (2marks)
    2. Roughage add bulk to the food hence facilitating peristalsis / offer grip to prevent constipation; (i) 
22.  
    1. The larger the surface area to volume ratio, the faster the rate of diffusion; (1mark acc. Reverse)
    2. Diffusion gradient; the higher the diffusion gradient (between two points) the faster the rate of diffusion; (1mark)
    3. Temperature- increase in temperature increases the rate of diffusion; (1mark)
23.  
    • Root hair cell      - Palisade cell       - Parenchyma cell 
    • Epidermal cell     -Guard cell            - Companion cell   
24.  
    • Stomata
    • Lenticels
    • Cuticles
25.  
    • Kingdom: Animalia. Rej: Animal or if first letter is small letter
    • Phylum: Arthropoda rej. Anthropoda / Athropoda / Arthropod if first letter is small letter
    • Class: Insecta rej Insect or if first letter is small letter
26.  
    1. Counter flow is a flow system in which blood and water (a fluid) flow in opposite directions within respiratory surfaces while parallel flow is a system in which blood and water (fluid) flow in the same direction within respiratory surfaces;
    2. Counter current flow; it increases efficiency in oxygenation of blood and maintains a steep concentration gradient;
27.  
    1. prothrombin
    2. K
    3. calcium ion
28.  
    1.  
       • Makes the skin and hair surface water proof.
       • To protect the skin against infection by bacteria and viruses (it’s a mild antiseptic)
       • Makes the skin and hair soft and supple
    2. The structure (blood vessel) constricts // contracts (vasoconstricts) and lies deeper in the skin so as to reduce heat loss from the body through radiation
29. Living things will show characteristics like feeding, excretion, reproduction, gaseous exchange, movement, respiration; irritability; growth and development.   (Any two)