Biology Paper 3 Questions, Answers and Confidential - Arise and Shine Mock Exams 2022

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INSTRUCTIONS TO THE CANDIDATES

  • Sign and write your Name and index Number in the spaces provided above.
  • Answer all the questions in the spaces provided.
  • You are required to spend the first 15 minutes off the 1 ¾ hours allowed for this paper reading the whole paper carefully before commencing your work.
  • Additional pages must NNOT be inserted.
  • Candidates may be penalized for recording irrelevant and incorrect spelling especially of technical terms.
  • Candidates should answer all the questions in English.

For Examiner’s Use Only

Question

Maximum Score

Candidate’s Score

1

13

 

2

14

 

3

13

 

Total Score

40

 

QUESTIONS

  1. You are provided with the specimen labeled M-soaked millet. Grind them using pestle and mortar, add some water to get fine solution label four clean test tubes; A, B, C and D. Put about 4ml of the solution into each of the four test tubes.
    1. To solution in test tube A, add some few drops of iodine. Shake the solution to mix well. Pour some little solution onto a white tile.
      1. Record your observation. (1 mark)
      2. Account for your observations in a) (i) above. (1 mark)
    2. Into solution in test tube B, add about 2ml of Benedict’s solution. Place it in a boiling water bath.
      1. After about 3 minutes, record your observation. (1 mark)
      2. What is your conclusion from observation in (b) i) above?

        For the remaining test tubes;-

    3. To each of test tube C, add about 3ml of solution labeled K. To test tube D and about 3ml of solution K and about 2ml of solution labeled L. Place both test tubes C and D in a water bath. Maintain the water bath at 37oC. Allow it to stand in the water bath for 30 minutes. After 30 minutes, remove the test tubes. Add about 2ml of Benedict’s solution to each test tube and shake well. Place the two test tubes in a boiling water bath. After about 5 minutes record your observations in the table below. (4 marks)

      Test tube

      Observation

      Conclusion

      C

         

      D

         
    4. Account for your observations in the test tubes C and D. (2 marks)
    5.                        
      1. Why was set up placed at 37ºC? (1 mark)
      2. Suggest identify of solutions K and L. (2 marks)
        K ................................ L .................................
  2. You are provided with a piece of animal organ labelled C
    1. Identify the organ. (1 mark)
    2. Explain why malfunctioning of this organ causes;
      1. Impairment of blood sugar regulation. (2 marks)
      2. Impairment of food digestion. (2 marks)
    3. Cut specimen C into two equal pieces, immerse one of the pieces in water inside a boiling tube and boil it for five minutes.

      Put 10ml of hydrogen peroxide in one boiling tube and label it D1, then put another 10ml of hydrogen peroxide into the other boiling tube and label it D2.
      Drop the fresh piece of organ C into D1 and the boiled piece into D2.
      1. Record your observation:
        D1 (1 mark)
        D2 (1 mark)
      2. Which homeostatic function of the organ C is being investigated. (1 mark)
      3. Account for the observation made in
        D1 (2 marks)
        D2 (2 marks)
    4. Name two diseases that affects organ C. (2 marks)
  3. The photographs below shows bones obtained from different regions of a mammalian body. The photographs are in different views.
    3 auygdauyd
    1. Identify the bones. (3 marks)
      A .
      B
      C
    2. Name the regions from which bone B was obtained from. (1 mark)
    3. State two distinguishing features of the bone in photograph labeled B. (2 marks)
    4. Name the part labelled T in the photograph of bone A and state its significance. (2 marks)
    5. With reason state the type of joint formed at the distal and proximal and of specimen C.(4 marks)
      1. Distal end ..
        Reason
      2. Proximal end
        Reason
    6. Name the bone that articulates with the proximal end of the bone in photograph labelled C. (1 mark)  

PRACTICAL CONFIDENTIAL

The information contained in this paper is to enable the head of the school and the teacher in charge to Biology to make adequate preparations. 
NO ONE ELSE should heave access to this paper or acquired knowledge of its contents.
Great have MUST be taken to ensure that the information herein does not reach the candidates either directly or indirectly.
 
Each candidate require the following;
  • One table spoonful of millet soaked for about 50 minute labeled M.
  • Measuring cylinder
  • 6 Labels
  • Thermometer
  • Means of timing (Stopwatch)
  • 0.1M Hcl labeled solution L
  • Four clean test tubes
  • Pestle and mortar
  • Scarpel/razor blade
  • Iodine solution
  • Benedict’s solution
  • Water bath
  • Source of heat
  • White tile
  • Solution of amylase/diastase enzyme labelled solution K
  • Source of distilled water
  • A piece of liver organs labelled C
  • 2 boiling tubs
  • Hydrogen peroxide (about 20m/s per candidate)

MARKING SCHEME

  1.                              
    1.                    
      1. Solution turns blue – black /blue/black
      2. Indicates presence of starch in the solution
    2.                    
      1. blue colour remains/persists/No observable colour change/No change in colour
      2. Absent of reducing sugars
    3.            

      Test tube

      Observation

      Conclusion

      C

      D

      Colour change to yellow/orange/brown

      Acc.colour change to green

      No colour change/blue

      Colour remains/persists

      Present of reducing sugars

      Green colour tied to little amount of reducing sugar

      Absence of reducing sugars

    4. C – Starch solution converted/hydrolysed to reducing sugars; the 30 minutes allowed hydrolysis of starch by solution K.
      D – The starch solution was not hydrolysed; hence absence of reducing sugar after 30 minutes; solution L prevented the hydrolysis by K.
    5.                    
      1. This is the human body temperature/I is the best temperature for human enzymes/favourable temperature/optimum temperature
      2. K – amylase enzyme/diastase
        L – Hydrochloric acid/enzyme inhibitor
  2.                      
    1. Liver
    2.                        
      1. Liver is responsible in control/regulation of blood sugar; using hormones insulin and glucagon.
      2. Liver synthesis bile from old red blood cells; bile is required in emulsification of fats.
    3.                  
      1. D1 - Rapid/fast effervescence/bubbling/fizzing
                  D2 – No effervescence/bubbling/fizzing
      2. Detoxification
        (Poisonous H2O2 is broken to water and oxygen) in presence of enzyes catalase
      3. D1 – presence of enzyme catalase; converts poisonous hydrogen peroxide to water and oxygen
        D2 – Absence of enzyme catalase; boiling/heating denatures the enzyme; hence no reaction took place.
    4. Liver cirrhosis
      Hepatitis A or B Acc/Hepatitis
      Jaundice
  3.                    
    1. A – Thoracic vertebra rej . Thoracic bone
      B - Lumbar vertebrae rej. Lumbar alone
      C - Humerus
    2. Abdominal region acc.lumbar region
    3.                      
      • Long transverse processes
      • Short broad neural spine
      • Extra processes/metapophysis
      • Large centrum.
    4.                    
      1. Identity – Neural spine
        Significance – Increase surface area for attachment of muscles.
    5.                      
      1. Hinge joint
        Reason – Presence of condyles/grooves
        Which articulate with depression of next bone
      2. Ball and socket joint
        Reason - Head shaped like a ball/rounded end
    6. Pectoral girdle.

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