Biology Paper 1 Questions and Answers - Mumias West Pre Mocks 2022

QUESTIONS

1.         
   1. State the function of a mirror in a light microscope. (1 mark)
   2. Give one reason why the coarse adjustment knob should not be used to lower the high power objective. (1 mark)
2. The set below illustrates a certain physiological process
          
   1.        
      1. Name the physiological process (1 mark)
      2. Give two examples of the process names in (a) (i) above in plants. (2 marks)
   2. State two ways by which the movement of dye molecules in the set up would be going down. (2 marks)
3. The table below shows the percentage concentration of certain substances in blood plasma glomerular filtrate and urine in a human being at a particular time.
   

   Percentage concentration
   Substance	Blood plasma	Glomerular filtrate	Urine
   Glucose	0.023	0.02	0.0
   Water	92.70	92.70	96.08
   Protein	5.69	0.0	0.0
   Urea	0.087	0.098	2.6

   1. Explain the likely impact on the composition of urine in case of the following:
      1. Vigorous physical exercises (2 marks)
      2. A meal rich in proteins (2 marks)
   2. Name the processes responsible for:
      1. Presence of glucose in glomerular filtrate (1 mark)
      2. Absence of glucose in urine (1 mark)
4. State three factors that affect the rate of diffusion. (3 marks)
5. How does nutrition as a characteristic of living organisms differ in plants and animals? (2 marks)
6. The diagram below represents a certain organism collected by a student at the sea shore.
   
   
   1. Name the class to which the organism belongs. (1 mark)
   2. Give three reasons for your answer in (a) above. (3 marks)\
7. The figure below is a fine structure of a generalized animal cell as seen under an electron microscope.
   
   
   1. Name the parts labeled A and B. (2 marks)
   2. How is the structure labeled B adapted to its function? (2 marks)
8. In an investigation, a student extracted three pieces of pawpaw cylinders using a cork borer. The cylinders were cut back to 50mm length and placed in a beaker containing a solution. The results after 40 minutes were as shown in the table below.
   

   Feature	Result
   Average length of cylinders (mm)	56 mm
   Stiffness of cylinders	Stiff

   1. Account for the results in the table above. (3 marks)
   2. What would be a suitable control set-up for the investigation? (1 marks)
9. The table below shows results of a study of three plants C, D and E growing in different habitats.
   

   Feature	Plant C	Plant D	Plant E
   Number of stomata on upper surface of leaf per square area	4	20	6
   Number of stomata on lower surface of leaf per square area	6	0	8
   Thickness of leaf cuticle (mm)	0.4	0.1	0.2
   Surface area of roots (cm3)	2000	1000	1200

   1. Which one of the plant C, D and E grows in an area of relatively low water availability?(1 mk)
   2. Explain your answer in (i) above. (2 marks)
10. The diagram below shows part of the mammalian system
    
    
    1. Name the parts labeled F and G. (2 marks)
    2. State one function of each of the parts labeled H and J (2 marks)
11. The diagram below shows a reproductive structure of a plant.
    
    
    1.        
       1. Identify the reproductive structure. (1mk)
       2. In which part of the reproductive system is the structure produced? (1mk)
    2. Name division of the plant that produces the reproductive structure above. (1mk)
    3. Name structures E and F (2mks)
12.        
    1. What is pollination? (1mk)
    2. Cross pollination leads to cross fertilization which results to hybrid vigour. State three mechanisms that encourages cross pollination instead of self pollination. (3mks)
13. Define the terms; (2mks)
    1. Ovulation
    2. Implantation
14. Explain why
    1. A pregnant woman needs to be on a diet rich in proteins and mineral salts such as calcium. (2mks)
    2. A drop in progesterone levels during pregnancy my cause miscarriage. (2mks)
15. Outline two precautions taken when collecting and observing specimens. (2mks)
16. Below is a diagram representing one of the apparatus used in biological studies?
    
    
    1. Identify the apparatus. (1mk)
    2. Name two animals which require the use of the apparatus during their collection. (2mks) 
17.      
    1. What are the benefits of scientific skills acquired in studying Biology? (2mks)
    2. Outline two ways in which an aircraft can be compared to a bird apart from flying. (2mks)
18. Name two structures used for gaseous exchange in plants. (2mks)
19. What is meant by each of the following?
    1. Pyramid of biomass? (1mk)
    2. Pyramid numbers?(1mk)
20.      
    1. Name the organism that;
       1. Causes malaria (1mk)
       2. Transmits malaria (1mk)
    2. State two control measures for malaria (2mks)
21.      
    1. What is meant by the term binomial nomenclature (1mk)
    2. State two guidelines that should be followed when typing scientific name. (2mks)
22. An individual is of blood group B positive.
    1. Name the antigens in the individual’s blood. (2mk)
    2. Give the reasons why the individual cannot receive from a blood group A donor. (2mks)
23. Colour blindness is a sex linked trait controlled by a recessive b. If a mother is a carrier and the father is normal, what is the chance that their son will be colour blind? Show your working. (3mks)
24. State two advantages of using a coverslips when preparing a specimen for observation under a light microscope. (2mks)

MARKING SCHEME

1.      
   1. State the function of a mirror in a light microscope. (1 mark)
      Reflects light (through the condenser) to object;
   2. Give one reason why the coarse adjustment knob should not be used to lower the high power objective. (1 mark)
      Can destroy the specimen (making the microscope dirty);
2.      
   1.      
      1. Name the physiological process. (1 mark)
         Diffusion;
      2. Give two examples of the process named in (a) (i) above in plants. (2 marks)
         Gaseous exchange/ excretion of CO₂ and oxygen;
         Translocation of materials;
         Absorption/ uptake of mineral ions/salts;
   2. State two ways by which the movement of dye molecules in the set up would be slowed down. (2 marks)
      Lowering temperature of the medium;
      Increasing thickness of the membrane;
      Use less dye and more water/ reduce concentration gradient;
3.      
   1.      
      1. Vigorous physical exercises(2 marks)
         Less water and urea; since some is excreted/eliminated through the skin (as sweat);
      2. A meal rich in proteins (2 marks)
         Increase amount of urea in the urine; due to deamination of amino acids (from protein)
   2. Presence of glucose in the glomerular filtrate
      Ultrafiltration; (1 mark)
4. Temperature, surface and thickness of membranes/changes that particles have to travels diffusion/concentration gradient, size/density of molecules medium of diffusion surface area to ratio
5. Plant make their own food from carbon (iv) oxide and water in the presence of flight/photosynthesis autotrophic, while animals cut ready made food (from plants and animals heterotrophic 2mks
6.      
   1. Crustaceae, ace crustacean 1mk
   2. Head fused with thoras thus cephelothorax;
      Have compound eyes/ a pair of compound eyes;
      Have five pairs of limbs/ 5-20 pairs of limbs,
      Have external gills;
7.      
   1. Nucleapore/ nuclear pore;
      Rough endoplasmic reticulum
   2. Surface area covered with ribosome’s; for protein synthesis/ channels for transport of protein
8.      
   1. The solution was hypotonic/less concentrated compared to the cell sap of pawpaw cylinder cells/cell sap hypertonic to the solution
      The tissue/ cells grained water by osmosis becoming turgid/longer/stiff
   2. Paw paw cylinder of the same size/length; placed in isotonic solution;
      Boiled paw paw cylinders of same size/lengths; placed in isotonic solution;
9.      
   1. Plant c 1mk
   2. Thick cuticle reduces water loss 3mks
      low number of stomata reduces water loss/leased number of stomata on upper surface reduces water loss;
      large root surface area enhances water absorption
10.      
    1. F -bronchiole
       G- Intestinal muscles/external intestinal muscle;
       Internal intercostals muscles
    2. (Pleural membranes) secrets/encloses pleural fluid to lubricate/protein lungs
       Diaphragm separates chest cavity from abdominal cavity/work to effect volume/pressure changes in chest cavity necessary for inhalation and exhalation (ventilation,
11.      
    1.      
       1. Pollen grains; Acc. Male reproductive gamete in flowing plants.
       2. Anther
    2. Spermatophyta
    3. E - Generative nucleus; rej. Generative nuclei
       F - Tube nucleus;
12.        
    1. Pollination is the transfer f pollen grains from anthens to stigma of flower of the same species.
    2.      
       1. Protandry
       2. Protogyny
       3. Self fertility or incompatibility
       4. Heterostyly
       5. Dioecism
          (Accept the first 3)
13.      
    1. Is the bursting of the graafian follicle of the ovary to release an ovum egg/egg
    2. The process by which the blastocyst becomes embedded in the inner lining of the uterus (endometrium)
14. Proteins are important for the formation of the tissues of the developing foetus
    Calcium is needed for formation of bones in the embryo.
15.           
    • Collect the number needed only
    • Use forceps or gloves when handling dangerous or stinging specimen
    • Immobile highly mobile specimens.
    • Keep collected specimens in a specimen bottle
    • Do not destroy or alter their natural habitat
    • After their use return them to their habitat
16.      
    1. Poofer
    2. Ants
       Crickets
       Spiders
17.        
    1. Develop ability to;
       Observe an organism
       Recording data
       Identifying
       Classifying
    2. Both oxidize organic substance to get energy
       Both get rid of waste products i.e. Water and Carbon (iv) oxide gas
       Both consume organic food substances.
18. Lenticels
    Stomata
    Root hairs of pneumatophores in aquatic plants
19.      
    1. Is a diagrammatic representation that show total dry mass of organisms present at each trophic level of a food chain
    2. Is a diagrammatic representation of total numbers of individual at each trophic level of a food chain.
20.      
    1.         
       1. Plasmodium ssp eg. P. vivax, P. ovale, p. falciparum p. malaria
       2. Female Anapheles mosquito
    2. Bush clearing e.g. Cutting tall grass and bushes around homes
       Spraying mosquitoes with insecticide to kill them.
       Use of electrical emissions that attract and shock mosquitoes
       Sleeping under treated mosquito nets
       Fumigating sleeping rooms with mosquito repellant sprays or coils
21.        
    1. Is the scientific double naming system of giving an organism two names, generic and specific name
    2. The first name is generic name followed by the specific name
       Generic name should start with a capital letter while the specific name is small letters
    3. Two names should be underlined separately in the manuscripts of italicized in typescript
22. Antigen B corresponding to antibody b in the donor, this will cause agglutination of blood.
23.     
    
24. Prevent dust from reaching the specimen
    Prevent the specimen from drying