In Drosophila melanogaster ebony body color is determined by

In Drosophila melanogaster, ebony body color is determined by the e allele. The e\' allele produces the wild type honey-colored body. In heterozygotes for the two alleles, a dark marking called the trident can be seen on the thorax, but otherwise the body is honey-colored. The e\' allele is thus considered to be incompletely dominant to the eallele. When female e\' e\' flies are crossed to male e\' eflies, what is the probability that progeny will have the trident marking? Animals with the marking mate among themselves. Of 300 progeny, how many would be expected to have a trident, how many would have ebony bodies, and how many would have honey-colored bodies?

Solution

(a) the females are e⁺e⁺ (gametes will be e⁺ and e⁺) while the males are (e⁺e) so the gametes will be (e⁺ and e) when the mating will take place then the forming progeny will be (e⁺e⁺, e⁺e, e⁺e⁺ and e⁺e) as it is given that heterozygous will have dark marking so 50% of the individuals mighht have trident.

(b) In respect to the above case none of the individual having ebony body will be formed beacuse mother is honey coloured body and father is heterozygous so he will also be honey coloured but with a dark marking hence the ratio comes to be 1:1.Total 300 progeny are there so 150 will be honey coloured and 150 will be trident.