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Biology Paper 2, Nov/Dec 2010  
Questions:   1 2 3 4 5 6 7 8   Main
General Comments

Question 8

(a) The diagram below is a student's illustration of the carbon cycle. Study it carefully and use it to
answer questions 8(a) (i) and (ii).

(i) List two things that are wrong with the diagram [2 marks]
                  (ii)          Explain the implication of the errors on the ecosystem. [2 marks]
(b) State six functions of public health authorities [2 marks]
           ( c) (i)          What is immunization? [2 marks]
                  (ii)         State two reasons why immunization of children is important [2 marks]



Question 8 was the less popular question in this section and candidates who attempted it did not do very well.

Some candidates felt that there was nothing wrong with the diagram but majority of candidates who attempted the question were able to point out the flaws namely that photosynthesis is giving up carbon chloride and carbon dioxide is being used up in burning/combustion.

Most of the candidates could only give one implication that "there will be too much carbon dioxide in the atmosphere" .

Other expected answers include:

The process of photosynthesis will no longer lead to purification of the atmosphere, because trees will result in release of carbon dioxide; the population of trees/plants are always more; so the quantity of carbon dioxide released will be much; this will lead to pollution of the atmosphere; depletion of the ozone layer; release of dangerous radiations; leading to cancer; mutation; death of organisms; deforestation/trees/plants will be cut to avoid pollution, this will result in erosion, leaching; soil infertility.

Only the process of burning or combusting will result in the purification of the atmosphere, this will result in depletion of fuel/minerals/fossils fuels.

Most candidates could correctly state functions of Public Health Authorities and the importance of immunization but many candidates listed treatment of war victims as one of the functions of Public a Health Authorities and so they lost the score.

Most of the candidates could define immunization and state why it was important for children




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