Biology Paper 3 Questions and Answers with Confidential - Samia Joint Mock Examination 2021/2022

INSTRUCTIONS TO CANDIDATES:

1. Write your name and index number in the spaces provided above
2. Sign and write the date of the examination in the spaces provided
3. Answer ALL the questions in this paper
4. You are required to spend the first 15 minutes of the 114 hours allowed for this paper reading the whole paper carefully before commencing your work.
5. The paper consists of 11 printed pages
6. Candidates should check the question paper to ascertain that all the pages are printed as indicated and that no questions are missing.

1. Using the piece of string provided, tie the visking tubing tightly at one end. Put 2cm of solution
   P into the visking tubing using a dropper to avoid spilling. Then tightly tie the other end and place it in a boiling tube containing 2cm of iodine solution.
   
   1.           
      1. Leave it for 5 minutes then record your results below. (1 mark)
         Observation:
      2. Account for your results answer in a (i) above. (2 marks)
   2.      
      1. Make a transverse section of specimen D provided and made a labeled drawing. (3 marks)
      2. Cut a strip of 4cm long by 2cm wide from the banana peel (of specimen D) and place on a petri dish containing solution L. Record your observation after 10 minutes in the table below. (2 marks)
         

         	Length at start of experiment	Length at end of experiment
         Strip of banana peel

      3. Account for your answer in b(ii) above. (3 marks)
   3. State the role of the process under investigation in organisms in la) (i) and in 1b) (ii) above. (3 marks)
      Process in 1 a) (i) (1 mark)
      Process in 1 b) (ii) (1 mark)
2. Below is a photomicrograph of blood smear showing several elements.
   
   
   1. On it label any four elements of blood (4 marks)
   2. Briefly explain the mode of action of elements M and J(2 marks)
      M..........................
      J....... ..
   3. What are the effects of high attitude on the numbers of element N.? (1 mark)
   4. State the function of element N and explain one functional adaptation of element N.
      1. Function of N (1 mark)
      2. Functional adaptation of N (2 marks)
   5. Study the diagrams below and answer the questions that follow.
      
      
      1. Name the parts labeled A, B, C and D (2 marks)
         A............
         B............
         C.............
         D............
      2. State the adaptation of the part labeled A to its function. (2 marks)
   6. Identify the structures that perform similar functions as D above in: -
      1. Amoeba........ (1 mark)
      2. Fish............ (1 mark)
3.      
   1. Examine photograph A, B1 and B2 carefully and answer the questions that follow. B2 was extracted from B1 (1 mark)
      
      
      1. What name is given to the coiled part labeled T found on specimen A
         T..........................
      2. Name the type of response exhibited by the coiled part on specimen A (1 mark)
      3. Name the stimulus responsible for the response named in (ii) above. (1 mark)
      4. Explain how the response exhibited by the coiled part on specimen A occurred. (2 marks)
      5. State the biological significance of the response described in (iv) above to the survival of the specimen. (1 mark)
   2. Use photographed specimen labeled B1 and B2 above to answer the questions below.
      1. State the agent of pollination for the specimen above. (1 mark)
      2. Give a reason for your answer (1 mark)
      3. Describe the external features of leaves of the specimen B2(3 marks)
      4. Based on the floral parts, state the class to which specimen B belongs. (1 mark)
      5. Give a reason for your answer in (iv) above (1 mark)

CONFIDENTIAL
REQUIREMENTS

1. 4cm³ of Iodine solution
2. 30cm Transparent ruler
3. Solution P – mix glucose, egg albumen and (6cm³) starch
4. Petri-dish (1)
5. Concentrated salt solution labeled L (10cm³)
6. Piece of visking tubing (4cm)
7. 2 pieces of 10cm string (thread)
8. One piece of raw mature banana
9. Scalpel / knife
10. One boiling tube
11. One wall clock per room

NB:

• Each candidate to provided with the above apparatus, specimens and chemicals
• Photographs for question 2 and 3 should be coloured

MARKING SCHEME

1.      
   1.      
      1. Content of visking tubing turns blue black / black dark blue / bluish black
      2. Iodine molecular (are small hence diffuse through visking tubing; iodine react with
         starch in the visking tubing to produce blue-black compound; starch molecules are too large to pass through the visking tubing
   2.      
      1. Ts of D
         
         Accuracy mark
         Drawing: Continuous outline
         All parts drawn (1 mark)
         Label Mark
         • Line must touch the structure
         • Correct spelling
         • Is pericarp is included it spoils for the three parts
           D= 2
           L = ²/₄ (2 marks)
      2. 
         

         	Length at start of experiment	Length at end of experiment
         Strip of banana peel	4cm	A figure slightly less than 4cm

         Reject if units not shown. (2 marks)
      3. Solution L is hypertonic; to (cells of specimen D) Cells of specimen D lose water; by osmosis and become flaccid;
         (4 max 3m)
   3.      
      1. Absorption of mineral salts by root hairs / absorption of digested food into blood stream / Gaseous exchange in plants / animals
         Transport of products of photosynthesis in plants; (any 1 – 1 mark)
      2.        
         • Absorption of water by root hairs
         • Support in herbaceous plants
         • Opening and closing of stomata
         • Feeding in insectivorous plants
         • Osmoregulation (any 1 – 1 mark)
2. 
        
   1. A - Blood Plasma
      B - Leucocyte (white blood cell)
      K - Platelets (thrombocytes)
      N- Red blood cells (Erythrocytes)
      Reject labels like; granulocyte, agranulocyte
      (Any correct label – 1 mark)
      Label line must touch the structure
   2. M - Move towards pathogen, engulf pathogen; and digest by lytic enzymes; by phagocylosis (max – 2 marks)
      J - Produces antibodies; which destroy / neutralize the effect of the pathogen. (2 marks)
   3. Increase in number (1 mark)
   4.      
      1. Element N
         Transport of respiratory gases / oxygen / carbon iv oxide.
      2. Biconcave increase surface area for diffusion of respiratory gases / oxygen / carbon ivoxide; lack nucleus to provide enough packing space for haemoglobin; Have haemoglobin which has a high affinity for oxygen. Has carbonic anhydrase for transport of carbon in oxide. (any one – 2 marks)
   5.      
      1.      
         1. Trachea
         2. Bronchus
         3. Pleural membrane
         4. Alveol
      2.      
         • Has rings of cartilage that keep it open
         • Has cilia that move mucus and dust particles to the top of the trachea
         • Lining secretes mucus which traps dust particles and micro-organisms
   6.    
      1. Cell membrane / plasma membrane / plasmalemma
      2. Cell filament
3.        
   1.      
      1. Name given to the coiled part labeled T found on specimen A
         Tendril; Reject wrong spellings, accept plural (1 mark)
      2. Type of response exhibited by the coiled part on specimen A (1 mark)
         Thigmostropism / Haptotropism
         Reject wrong spellings
      3. Stimulus responsible for the response named in (ii) above. Contact
         Reject tough (1 mark)
      4. How the response exhibited by the coiled part on specimen A occurred (3 marks)
         Due to contact; the auxins / IAA moved away from the surface of contact / accumulated on the surface away from contact; where they caused faster growth / cell elongation hence curing/coiling (around a support)
      5. Biological significance of the response described in (iv) above to the survival of the specimen. (1 mark)
         Has tendril to provide support; (by coiling around firm support) / to reach for light (1 mark)
   2.      
      1. The agent of pollination for the specimen B
         Insects (1 mark)
      2. Reason
         Brightly coloured petals (2 marks)
      3. The external features of leaves of the specimen B2
         
         • Net veined
         • Serrated blade / serrated leaf margin
         • Pointed apex of leaf. (1 mark)
      4. The class to which specimen B belongs
         Dicotyledonae; Reject dicotyledon(1 mark) 
      5. Reason for answer in (iv) above
         Floral parts are in 5 / multiples of Ss.