a. Produce a key to clearly show the nature of the alleles associated with the eye colour in
this species of Drosophila, and in each case justify your choice of letters and / or style of
presentation to best depict the genetics involved. (3 marks)


b. State the type of genetics involved in terms of body colour, justifying your answer with the evidence from the question details given. (2 marks)

d. A red-eyed female with a grey body is crossed with red-eyed male with a yellow body –without further information and using the information you have provided in your keys in partsB and D, what are the possible genotypes of these two flies and why?
(Hint: You need to show the genotypes as an expression of both genes together -and you need to explain the logic of how you have arrived at your answer -NO genetic proofing / diagrams such as Punnet squares required at this stage).
(10 marks)

e) The pair of fruit flies (given in part d) produce 320 offspring together from a single mating:
57 red-eyed females with grey bodies, 61 red-eyed females with yellow bodies, 22 brown-
eyed females with grey bodies, 20 brown-eyed females with yellow bodies.
59 red-eyed males with grey bodies, 63 red-eyed males with yellow bodies, 20 brown-eyed
males with grey bodies, 18 brown-eyed males with yellow bodies.
From this information only (NO genetic diagrams required), what evidence and logic can
you use to deduce the genetic identity of the parent flies? (4 marks)
f) Having identified the genetic identity of the parent flies, fully proof your answer to show the
simultaneous transmission of the two genes involved to give rise to the progeny given in part
g), with the use of genetic diagrams and summaries as required. (Hint: you are only required