Use the information below to answer questions 4(a)(i) and 4(a)(ii).
    Hb Are presents normal haemoglobin, 
    HbS represents sickled haemoglobin.

 

a. A female heterozygote for sickle cell married a sickler.  With the aid of a genetic diagram, determine the:
    (i)  possible genotypes of their offspring;    [8  marks]
    (ii)  phenotypic ratio of the offspring.    [2  marks]

b. Explain briefly the reason why a Rhesus negative woman married to a Rhesus positive man might lose her second  pregnancy.    [5 marks]

c. Name two examples of features in animals that support the theory of use and disuse of body parts as used by Lamarck.    [2 marks]

d. List three structures in mammals that are vestigial.    [3  marks]