Q. The recessive alleles k (kidney-shaped eyes instead of wild-type round), c (cardinal-coloured eyes in the place of wild-type red), and e (ebony body instead of wild-type gray) identify three genes on chromosome 3 of Drosophilia. Females with kidney-shaped, cardinal coloured eyes were mated with ebony males. The F1 was wild type. While F1 females were test-crossed with kk cc ee males, the next progeny phenotypes were obtained-

k c e 3
k c + 876
k + e 67
k + + 49
+ c e 44
+ c + 58
+ + e 899
+ + + _ 4
Total 2000

a. find out the order of the genes and the map distance between them.

b. sketch the chromosomes of the parents and the F1.

c. analyse interference and say what you think of its significance.