waecE-LEARNING
Biology Paper 1 Practical, May/June 2012  
Questions:   1 2 3 4   Main
General Comments
Weakness/Remedies
Strength























Question 1

LIST OF SPECIMENS PROVIDED
SPECIMEN  A:  GARDEN EGG
SPECIMEN B:   TRIDAX FRUIT
SPECIMEN C:   GRAIN WEEVIL
SPECIMEN D:    TICK
SPECIMEN E:     RAT/GUINEA PIG
SPECIMEN J:      TILAPIA FISH (WET PRESERVED)
SPECIMEN K:      TOAD (WET PRESERVED)
SPEICMEN L:       LIZARD (WET OR DRY PRESERVED)

      Question 1
      Study carefully specimens A and B and use them to answer questions
      1(a) to 1(c).

  1.  (i)  Name the types of fruit in specimens A and B with reasons                        [ 4 marks ]

(ii)   Make a drawing, 8 – 10 cm long of the lateral view of
         Specimen B and label fully.                                                                              [ 10 marks ]

  1.   Describe the modes of dispersal of specimens A and B.                                     [ 6 marks ]
  2.    In a tabular form, state five differences between specimens A and B             [ 5 marks ]



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OBSERVATION

This was the less popular question in this  section.  Most candidates could not correctly name the type of fruits in specimens A and B.  Some wrote that specimen A is a succulent, true fruit
While specimen B is a dry indehiscent fruit.  Some candidates who got the correct answer     missed the mark because of wrong spellings.  The expected answers were:
Specimen A/Garden egg is a Berry
Specimen B/Tridax fruit is a Cypsela.
They could not state the reasons correctly.
Expected answers include:
A/Berry- it has a fleshy  pericarp with many seeds embedded in it.
B/Cypsela    -  fruit bears a hairy calyx/hairy pappus/parachute;
                      -  dry single seeded fruit.

 Most candidates performed fairly in the diagram of specimen B/Tridax but did not show the rachis of the pappus with double lines and did not conform to size specifications.  This led to them scoring low marks.

Only few candidates could correctly state the modes of dispersal of specimens A and B and correctly state five differences between the specimens.   Expected answers include:

b)(i)      Modes of dispersal
            A/Garden Egg
          The fruit is soft and edible;
           Man and animals eat the soft pericarp;
           The seeds are spat out /egested /scattered.            
               B/ Tridax
            - Feathery papus traps air;
            - this increases the surface area of the fruit with respect to the volume;
            - so reduces the weight of the fruit;
            - to be blown and dispersed by the wind;
            - tough (dry) pericarp protect the seed embryo.       
                                         Differences between specimens A and B
            Specimen A(Garden Egg)                              Specimen B(Tridax Fruit)

  •  Fleshy pericarp                                        Dry pericarp;
  • Smooth epicarp/fruitwall                           Hairy epicarp;
  • No pappus                                                 Pappus present;
  • Calyx beneath fruit                                   Calyx (pappus) on top of fruit;
  • Calyx present                                            Calyx modified into pappus;
  • Large fruit                                                 Small fruit;
  • Heavy fruit                                                Light (in weight) fruit;
  • Green/white/yellow in colour                     Brown in colour.

 

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