Biology Paper 3 (Practical), WASSCE (PC), 2022

Question 3


  1. The diagrams below are illustrations of organisms. Study it and answer questions3(a) to 3(e).



(a)        (i)         Name organisms D, E, F, G and H.
                                                                                                [5 marks]
(ii)        Classify eachof organisms D, E and F into their kingdoms.
[5 marks]
(iii)       State one way by which organisms D, E, F, G and H are of economic
importance in their habitats.                                                   [5 marks]

(b)        Complete the table below by grouping organisms D, E, F, G and H under the appropriate headings.

Beneficial to industries

Disease-causing

Beneficial to the environment

 

 

 

 

 

 

 

 

 

                                                                                                                        [7 marks]

(c)        State the mode of reproduction in each of organisms D, E, F, G and H.
                                                                                                            [5 marks]

(d)        Which of organisms D, E, F, G and H is associated with the following terms?

(i)         crystallization:
(ii)        hyphae:
(iii)       single cell protein:
(iv)       capsule formation:
(v)        unicellular:
[5 marks]        

Observation

Most candidates performed averagely well in this question.
Many of them were able to name organisms D, E, F, G andH and also give the Kingdom of organisms D, E andF, but lost almost all the marks to spelling errors.

Some candidates could not state the economic importance of organisms D, E, F, G and H to their habitats.

Some candidates were able to group organisms D, E, F, G and H into beneficial to industries, disease causing and beneficial to environment; while some did not even know what they were doing.
A few candidates were able to answer question 3 (d) perfectly well.
The expected answers are:

(a)(i)    Name of Organisms
D         -           Rhizopus/mucor/bread mould/mold
E          -           Amoeba
F          -           Bacterium
G         -           Yeast/Saccharomyces
H         -           Virus

(ii)              Classification of D, E, and F
D         -           Fungi
E          -           Protoctista/Protista
F          -           Monera

(iii)              Economic Importance
D- it is a decomposer/causes disease in plants
E - forms part of food chain/causes diseases
F - causes diseases/useful in industries
G - used as food/useful in industries/winemaking/ breweries/causes diseases
H - causes diseases

(b)                   Table


Beneficial to industries

Disease-causing

Beneficial to the environment

Yeast/G

Amoeba/E

Rhizopus/mucor/mould

Bacterium/F

Yeast/G

Mold/D

 

Bacterium/F

Amoeba/E

 

Virus/ H

 

           

(c)        Mode of Reproduction
D         -           sporulation/spore formation/conjugation/sexual reproduction
E          -           binary fission/asexual reproduction
F          -           binary fission/asexual reproduction
G         -           budding/asexual reproduction
H         -           replication within a living host/cell