Biology Paper 3 Questions and Answers - Form 4 Term 1 Opener Exams 2021

BIOLOGY
PAPER 3
(PRACTICAL)
FORM 4 TERM 1 OPENER EXAMS
TIME: 1 ¾ HOURS

INSTRUCTIONS TO CANDIDATES

• Answer all the questions
• You are required to spend the first 15 minutes of the 1¾hrs allowed for this paper reading the whole paper carefully before commencing your work.

1. You are provided with specimen labelled F. Examine the specimen.
   1. With reasons state the type of fruit specimen F is. (1mk)
      Reason (1mk)
   2. Carefully open specimen F to expose it’s contents
      1. State the type of placentation in the specimen. (1mk)
      2. Draw and label the opened specimen. (5mks)
      3. Work out your magnification. (2mks)
   3. Remove the seeds and crush them using a mortar and pestle to make a paste. Add alittle water to make about 10ml solution of the paste.
      Using the reagents provided test for the food substances present in the juice. Record the food substances being tested, procedures, observation and conclusion in the table below. (6marks)
      

      FOOD SUBSTANCE BEING TESTED	PROCEDURE	OBSERVATION	CONCLUSION

2. Identify the specimens in the photograph using the key and outline the steps followed to identify each specimen. (8mks)
   
   1.      
      1. Animals with a backbone ………………………………………………. Go to 2
      2. Animals without a backbone ……………………………………………. Go to 5
   2.    
      1. Animals with wings………………………………….…………….... Eagle
      2. Animals without wings …………………………………………………… go to 3
   3.     
      1. Animals which live in water all the time………………………………… go to 4
      2. Animals which live in water some time………………………………….. Frog
   4.     
      1. Animals with fins ……………………………………………………… Fish
      2. Animals without fins ………………………………………………….. Turtle
   5.     
      1. Animals with legs ………………………………………………………. Go to 6
      2. Animals without legs …………………………………………………… go to 7
   6.     
      1. Animals with six legs ……………………………………………………... Butterfly
      2. Animals with eight legs ……………………………………………………. Spider
   7.     
      1. Animals with a shell…………………………………………………………. Snail
      2. Animals without a shell…………………………………………………….. go to 8
   8.     
      1. Animals with a jelly-like body ……………………………………………… go to 9
      2. Animals without a jelly-like body …………………………………………... Starfish
   9.      
      1. Animals with a segmented body …………………………………………….. Earthworm
      2. Animals without a segmented body …………………………………………. Octopus
         
         
         

         SPECIMEN	STEP FOLLOWED	IDENTIFY
         A
         B
         C
         D
         E
         F
         G
         H

         
         
         
3. Below are photographs of specimens obtained from plants. Examine the photographs.
   
   1. In the table below name the mode of dispersal and the features that adapt the specimens(s) to that mode of dispersal. (12marks)
      

      Specimen	Mode of dispersal	Adaptive feature
      K
      L
      M
      N
      P
      Q

      
      
      
   2.    
      1. Label any two parts on specimen (L ( on the diagram) (2mks)
      2. State the type of placentation in specimen L. (1mk)
   3. Name the structure labelled W on specimen P. (1mark)

CONFIDENTIAL

1. A mature pea pod.
2. Mortar and pestle
3. Distilled water
4. A small beaker
5. 3 test tubes
6. Test tube holder
7. Benedict’s solution
8. Iodine solution
9. 1% copper (II) Sulphate
10. 10% Sodium Hydroxide
11. Means of heating

MARKING SCHEME

1. You are provided with specimen labelled F. Examine the specimen.
   1. With reasons state the type of fruit specimen F is. (1mk)
      • Legume
        
        Reason (1mk)
      • Pericarp has longitudinal margins (lines of weakness).
      • Pericarp enclose the seeds inform of a pod.
      • Marginal placentation, develops from superior ovary
        
        
   2. Carefully open specimen F to expose it’s contents
      1. State the type of placentation in the specimen. (1mk)
         Marginal placentation
         
         
      2. Draw and label the opened specimen. (5mks)
         
      3. Work out your magnification. (2mks)
         Magnification =         Length of diagram         
                                Actual length of the specimen
         
         
   3. Remove the seeds and crush them suing a motar and pestal to make a paste. Add alittle water to make about 10ml solution of the paste.
      Using the reagents provided test for the food substances present in the juice. Record the food substances being tested, procedures, observation and conclusion in the table below.
      
      

      FOOD SUBSTANCE BEING TESTED	PROCEDURE	OBSERVATION	CONCLUSION
      Starch	To the solution add 2 drops of iodine solution	Colour of iodine turns to blue black	Starch present
      Proteins	To the solution add sodium Hydroxide solution followed by copper (II) sulphate solution drop wise	Purple colour is observed	Protein present
      Reducing sugars	To the solution add equal amounts of benedicts solution and gently heat to boil	Blue colour of Benedict’s turns to green- yellow orange	Reducing sugar present

      
      
      
2. Identify the specimens in the photograph using the key and outline the steps followed to identify each specimen. (8mks)
   
   
   1.    
      1. Animals with a backbone ………………………………………………. Go to 
      2. Animals without a backbone ……………………………………………. Go to 5
   2.        
      1. Animals with wings………………………………………….... Eagle
      2. Animals without wings …………………………………………………… go to 3
   3.      
      1. Animals which live in water all the time………………………………… go to 4
      2. Animals which live in water some time………………………………….. Frog
   4.      
      1. Animals with fins ……………………………………………………… Fish
      2. Animals without fins ………………………………………………….. Turtle
   5.      
      1. Animals with legs ………………………………………………………. Go to 6
      2. Animals without legs …………………………………………………… go to 7
   6.      
      1. Animals with six legs ……………………………………………………... Butterfly
      2. Animals with eight legs ……………………………………………………. Spider
   7.      
      1. Animals with a shell…………………………………………………………. Snail
      2. Animals without a shell…………………………………………………….. go to 8
   8.     
      1. Animals with a jelly-like body ……………………………………………… go to 9
      2. Animals without a jelly-like body …………………………………………... Starfish
   9.      
      1. Animals with a segmented body …………………………………………….. Earthworm
      2. Animals without a segmented body …………………………………………. Octopus
         
         

         SPECIMEN	STEP FOLLOWED	IDENTIFY
         A	1a, 2a	Eagle
         B	1a 2b,3a, 4a	Fish
         C	1b,5b,7b,8a,9a	Earthworm
         D	1a,2b,3a,4b	Tortoise
         E	1b, 5b,7b,8a,9b	Octopus
         F	1b,5b,7b,8b	Starfish
         G	1b,5a,6b	Spider
         H	1a,2b,3b	Frog

3. Below are photographs of specimens obtained from plants. Examine the photographs.
   
   
   1. In the table below name the mode of dispersal and the features that adapt the specimens(s) to that mode of dispersal.
      

      Specimen	Mode of dispersal	Adaptive feature
      K	Animal	Hooks/hook
      L	Animal	Fleshy/juicy
      M	Wind	Parachute/Hair papus Hair-lice projection
      N	Wind	Winged pericarp Wing-like projections
      P	Animal	Fleshy
      Q	Self/self explosive  mechanism	Sutures/lines of weakens

      
      
      
   2.        
      1. Label any two parts on specimen (L ( on the diagram) (2mks)
         Epicar
         mesocarp
         Endocarp
         Seed
         placenta
         
         
      2. State the type of placentation in specimen L. (1mk)
         Axile
         
         
   3. Name the structure labelled W on specimen P.
      W – Seed/Endocarp