Biology Paper 1 Questions and Answers - Sunrise Pre Mock Exams 2023

INSTRUCTIONS TO CANDIDATES

•  Answer ALL questions.

1. What is the function of the following in a microscope?
   1. Mirror (1mk)
   2. Diaphragm (1mk)
2. Use the chart below to answer the questions that follow
   
   Name: -
   1. The blood cell represented by A (1mk)
   2. Metal ion represented by B (1mk)
   3. End product represented by C (1mk)
3. Below is a nucleotide strand
   A – A – G – T – C
   1. Is it a DNA or RNA strand? Give a reason (2mks)
   2. Give the bases which would appear on the complimentary nucleotide strand (1mk)
4. Below is a diagram of a white blood cell.
   
   
   1. Describe how the bacteria got into the cell (2mks)
   2. What happens to the bacteria once in the cell? (1mk)
5. Give three reasons why mitosis is important in living organisms (3mks)
6. Give the characteristics which adapt flowers for wind pollination (4mks)
7. Name one waste product that is :
   1. Almost absent in the renal vein but is present in the renal artery (1mk)
   2. Transported in the blood but not removed by the kidneys (1mk)
8. State two functions of the large intestines in human beings (2mks)
9. Identify the mode of feeding of the animal whose dental formula is given below.
   
   1. Mode of feeding (1mk)
   2. Give a reason for your answer in (a) above. (2mks)
10. Name the agent that causes:-
    1. Cholera (1mk)
    2. Typhoid fever (1mk)
    3. Amoebic dysentery (1mk)
11. Outline three roles of active transport in the human body (3mks)
12. State three ways in which nitrogen in the air is made available for plant use (3mks)
13. In an attempt to estimate the number of weaver birds in a small woodland 435 were captured , marked and released. Three days later , 620 were captured 75 of which were marked.
    1. What is the name of the sampling method described above. (1mk)
    2. Calculate the approximate size of the weaver bird population in the woodland. (2mks)
    3. Give one disadvantage of this method. (1mk)
14.  
    1. Name the hard body covering found in organisms in Arthropoda (1mk)
    2. State three uses of the structure mentioned in (a) above (3mks)
15. Study the diagram below and use it to answer the questions that follow
     
    1. Mention the equivalent of the following in the mammalian breathing mechanisms:-
       1. Bell jar (1mk)
       2. Balloons (1mk)
    2. Does the diagram represent inhalation or exhalation? Give one reason for your answer (2mks)
16. Explain two advantages of endoderms like man over ectoderms like lizards (2mks)
17.  
    1. Name the property that enables lipids to be stored in tissues of organisms (1mk)
    2. State two reasons why a camel stores large fat reserves in its body (2mks)
18. Below are cross sections of two fruits. Study them and answer the questions that follow
    
    1.  Name the parts labelled
       1. A……………………………………………………………………. (1mk)
       2. B …………………………………………………………………… (1mk)
    2. Name the type of placentation in fruit (2mks)
       1. P……………………………………………………………………
       2. Q……………………………………………………………………
19. Which region of mammalian digestive tract does digestion of fats begin? (1mk)
20. A Rhesus positive man, heterozygous for the trait is married to a rhesus negative woman. Carry out a genetic cross to show the offsprings of this couple.
21. The diagram below represents a stage during cell division.
            
    
    1. Identify the stage of cell division. (1mk)
    2. Give two reasons for your answer (a)i) above (2mks)
    3. Name the structure labelled M. (1mk)
22. State two organelles absent in members of kingdom monera but present in members of kingdom protoctista (2mks)
23. Name the substance produced during anaerobic respiration in animals and state why it should be got rid off immediately (2mks)
24. What makes it difficult for seeds to germinate at the following temperatures:
    1. 0°c
    2. 47°c
25. State two major functions of adipose tissue (fat) in mammals (2mks)
26. Below is an equation for respiration
    C₅₇H₁₀₄O₆ + 80O257CO₂ + 52H₂O + Energy
    1. Name the type of respiration taking place (1mk)
    2. Calculate the respiratory quotient (RQ) (2mks)
    3. Identify the type of food being metabolized. (1mk)
27. State one significance of interphase in cell division (1mk)
28.  
    1. What is the role of light in the light stage of photosynthesis? (1mk)
    2. What are the products of the light stage of photosynthesis? (2mks)

MARKING SCHEME

1.  
   1. Mirror – reflects light through the condenser to the object (1mk)
   2. Diaphragm – regulates the amount of light passing through the condenser to illuminate the specimen; (1mk)
2.  
   1. Platelets; (1mk)
   2. Calcium ions; (1mk)
   3. Fibrin; (1mk)
3.  
   1. DNA; base thymine is present (Thymine is absent in RNA strand); (2mks)
   2. T – T – C – A – G; (1mk)
4.  
   1. An invagination develops at the area of contact with the bacteria/the cell membrane fold and cytoplasm flow around the bacteria forming a food vacuole/phygocytic vesicle; a process called phagocytosis (2mks)
   2. Lysosomes secrete enzymes into the food vacuole/phagocytic vessicle; digestion occurs; soluble food diffuses into the cell; undigested materials are expelled when the vacuole moves to the edge and fuses with plasma membrane (2mks)
5. Growth; repair of tissues, maintenance of genetic material/retain chromosome number, asexual reproduction; (3mks)
6. Large quantities of pollen grains; smooth pollen grains; loosely hanging anther; small light pollen grains; large fatherly stigma; long filament (any 4; 4mks)
7.  
   1. Urea;
   2. Carbon (iv) oxide;
8.  
   • Absorption of water mineral salts e.g. iron, calcium; and absorption of vitamins;
   • Secretion of mucus that holds faecal matter and lubricates the intestinal wall for smooth passage of faeces; (2mks)
9.  
   1. Herbivorous rej. Herbivore (1mk)
   2. Absence of incisors and canines on the upper jaw. (2mks)
10.  
    1. Vibrio cholerae;
    2. Salmonella typhi;
    3. Entamoeba hystolytica; (3mks)
11.  
    • Reabsortion of glucose and some mineral salts by the kidney tubules;
    • Absorption of digested food, mineral salts and vitamins from the alimentary canal into the blood stream ;
    • Excretion of waste products from cells; reabsorption of useful materials into the bloodstream from tissue fluid; (any 3; 3mks)
12.  
    • By rhizobium bacteria into root nodules of leguminous plants;
    • By action of lightning;
    • By azotobactor, chlostridium;
    • By haber process/industrial fixation
      (Any 3; 3mks)
13.  
    1. Capture recapture method. (1mk)
    2. P = Fm x sc
                 MR
         = 435 × 620
                  75
       =3596 weaverbirds.   (2mks)
    3.  
       • The released animals may not mix freely .
       • Some organism may move in and out of the study area. (1mk)\
14.  
    1. Exoskeleton/cuticle; (1mk)
    2. Provide a large surface area for muscle attachment; protect internal organs from injury; prevent entry of harmful micro-organisms (any 3; 3mks)
15.  
    1.  
       1. Bell jar – ribcage/thorax; (1mk)
       2. Balloons – lungs; (1mk)
    2. Inhalation; because balloons are filled with air; the rubber sheet representing diaphragm is flattened; (2mks)
16.  
    • Endoderms are active throughout while ectoderms are active when the environmental temperatures are low;
    • Endoderms are widely distributed in different areas while ectoderms are found in areas with relatively high temperatures (2mks)
17.  
    1. They are inert;
    2. The fats are a source of metabolic water; they are a source of energy;
18.  
    1.  
       • A – Seeds; (reject seed) (1mk)
       • B – Placenta; (1mk)
    2.  
       • P – Parietal; (1mk)
       • Q – Free central; (1mk)
19. Duodenum;
20.  
    
21.  
22. Mitochondrion; nuclear membrane; (2mks)
23. Lactic acid; toxic/poisonous to the body cells;
24.  
    1. At 0°c the enzymes responsible for germination are inactivated;
    2. At 47°c the enzymes are denatured;
25.  
    • Insulate the body;
    • Oxidized to release energy and water when carbohydrates are exhausted; (2mks)
26.  
    1. Aerobic respiration (1mk)
    2. RQ = CO₂ produced (1mk)
                  O₂ consumed
       = 57 (2mks)
          80
       = 0.7
    3. Fats/lipids (1mk)
27. Replication of organelles; duplication of DNA; production of energy (ATP) for entire cell division (1mk)
28.  
    1. To break down water into its components /splits water molecules into oxygen and hydrogen ions;
    2. Hydrogen; oxygen; chemical energy/ATP;