SECTION A: (70%)
- (a) Siwemas a woman of blood group type A claims that Juma aman of blood type B is a father of her child Janks who is of blood type O.
Explain the validity of the woman claims.
(b) Two new born babies were accidentally mixed up in Hospital. The Blood test were carried and suvealed the following results.
Baby 1 Type O
Baby 2 Type A
Mrs Samuel Type AB
Mr. Samuel Type A
Mr. Mitowingi Type B
Mrs Mitoming Type B
From the evidence shown above, show which baby belongs two which parents.
2. (a) (i) What is a genetic code?
(ii) Explain the properties of the genetic code
(b) Describe the formation of the following non-Mendelian phenotypic ratios.
[*]Dihybrid ratio 9:7
[*]Dihybrid ratio 9:3:4
[*]Dihybrid ratio 3:1
[*]Monohydrid ratio 2:1
[*]Dihybrid ratio 1:2:1
3. (a) Expalin how a quadrat can be used to estimate population size
with respects of species distribution namely,
Species frequency, species cover and species density.
(b) The estimation of grass hoppers in a secluded area 675 grass hoppers were netted, marked and released.
On the second day 912 – grass hoppers were netted and of these 179 had been marked. What was the estimate size of the grasshopper population?
4. Describe how the following below are involved in the process of protein synthesis
(a) RNA polymerase
(b) Messenger RNA
© Transfer RNA
(d) UAA, UAG and UGA colons
5. (a) Define the following terms.
(iii) Food chain
(iv) Food web.
(b) What are the significances of studying population using food web, rather
than chains, in ecology.
© Refering to the trophic levels of a pyramid of numbers illustrate how energy
is lost while passing through the levels.
6. (a) Define the following terms
(b) Explain clearly four points which show the significance of an ecological study.
7. State three ecological pyramids and state the limitations of each.
8. (a) Name the two differences between the X and Y chromosomes of humans.
(b) The alleles for both haemophiliacs and colour blindness are inherited in the same fashion, that is, sex linked in population. Explain why there are more colour blind individuals than haemophiliacs?
SECTION B: (30%)
9. (a) Write short notes on
(i) Interspecific competition
(ii) Intraspecific competition
(iii) density dependent factors
(iv) Interspecific competition
(b) Point out three (3) structural differences between DNA and RNA.
10. Explain the following chromosomal mutation
11. Janeti a woman of child bearing age, requires blood transfusion before she has had any child. Blood testing reveals that she is of blood type A – from which groups will she safely get blood bearing she is married to a man with blood type B+
12. (a) Define the term mutation.
(b) (i) State the causes of mutation
(ii) Name the two (2) types of mutation
(iii) List the two (2) effects of mutations.
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