Question

When Morgan crossed yellow bodied and white
eyed female to wild type male, in F, progeny
(1) All males were wild type
(2) All females were identical to females of
parental generation
(3) Females were heterozygous for both the
characters
(4) Males were yellow bodied and red eyed​

Answer 1

Answer:

3. Females were heterozygous for both the

characters

Explanation:

Morgan and his students have found that linked genes show varied recom­binations, some being more tightly linked than others, (i) In Drosophila, crossing of yellow bodied (Y) and white eyed (W) female with brown bodied (Y+) red eyed (W+) male produced F1 to be brown bodied red eyed. On intercrossing of F1 progeny, Morgan observed that the two genes did not segregate independently of each other and, therefore, the F2 ratio deviated significantly from expected 9: 3: 3: 1 ratio. He found 98.7% to be parental and only 1.3% recombinants. (ii) In a second cross in Drosophila between white eyed and miniature winged (wwmm) female with wild type or red eyed normal winged (w+w+m+m+) males, all the F1 were found to be of wild type, i.e., red eyed and normal winged. An F1 female fly was then test crossed with white eyed and miniature winged male. 62.8% of the progeny was of parental types while 37.2% were recombinants.