KNEC KCSE Biology Paper 2 – 2014 KCSE COMA Joint Exam

Examine the diagram below and use it to answer the questions that follow.

(a) Name the parts labeled. (3mks)
B __________________________________________________________________________ C __________________________________________________________________________ D __________________________________________________________________________
(b) What is substance which makes up part labeled A? (1mk) ____________________________________________________________________________
(c) Name the process by which mineral salts move into structure B. (1mk) ____________________________________________________________________________
(d) Explain what happens when a red blood cell is put in distilled water. (3mks) ____________________________________________________________________________
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The figure below is a pedigree showing the inheritance of colourblindness, a disease transmitted
through a recessive gene located on the X-chromosome.

(a) Using the symbol N for normal gene and n for colourblind gene, write down the genotypes
of parents 1 and 2. (2mks) ____________________________________________________________________________
____________________________________________________________________________
(b) Work out the possible genotypes of the children 3, 4 and 5. (4mks)
(c) The diagrams below illustrate some chromosome mutations.

Identify the mutations. (3mks)
A __________________________________________________________________________

B __________________________________________________________________________

C __________________________________________________________________________

The diagram below shows structures of the bat wing and human arm.

(a) These structures are thought to have same ancestral origin. State one structural similarity
and one adaptational difference between the two.
(i) Structural similarity. (1mk) ______________________________________________________________________
(ii) Adaptational difference. (2mks) ______________________________________________________________________
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(b) Give two other examples of structures in nature that show the type of evolution as in
(a) above. (2mks) ____________________________________________________________________________
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(c) Distinguish between the terms ‘chemical evolution’ and ‘organic evolution’. (2mks) ____________________________________________________________________________
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(d) What is the study of fossils called? (1mk) ____________________________________________________________________________

The diagram below represents some hormones, their sources and functions in a mammal.

(a) Identify the gland described as master gland. (1mk) ___________________________________________________________________________
(b) Name the hormones:- (4mks)
II __________________________________________________________________________
III _________________________________________________________________________

V __________________________________________________________________________

VI _________________________________________________________________________
(c) Describe the consequences of deficiency of hormone II in man. (2mks) ____________________________________________________________________________
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(d) Other than stimulate development of uterine wall, suggest two other functions of hormone
VI. (2mks) ____________________________________________________________________________
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Ascaris lumbricoides is an endoparasite.
(a) Name the genus to which it belongs. (1mk) ____________________________________________________________________________
(b) State the habitat of the organism. (1mk) ____________________________________________________________________________
(c) State three ways in which the organism is adapted to living in its habitat. (3mks) ____________________________________________________________________________
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(d) Mention three ways of preventing spread of the parasite. (3mks) ____________________________________________________________________________
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The table below shows how the quantities of sweat and urine vary with external temperature.

(a) On the same graph, plot the quantities of urine and sweat produced against the external
temperature. (7mks)

(b) At what temperature are the amounts of sweat and urine produced equal? (1mk) __________________________________________________________________________
__________________________________________________________________________

(c) What happens to the amount of sweat produced as the temperature rises? Explain the
observation. (3mks) __________________________________________________________________________
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(d) Explain the observation made on the amount of urine produced as the temperature
increases. (3mks) __________________________________________________________________________
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(e) How is the skin adapted for temperature regulation? (6mks) __________________________________________________________________________
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Describe the structural adaptations of the mammalian heart to its function.

Describe how water moves from the soil to the leaves in a tree.