Can someone help me with these two questions please? 1) In the fruit fly, Drosop

Question

Can someone help me with these two questions please?

1) In the fruit fly, Drosophila melanogastrer, the allele for dumpy wings (d) is recessive to the normal long-wing allele, (D) and the allele for white eye (w) is recessive to the normal red-eye allele (W). In a cross of DDWW with Ddww, what proportion of the offspring are expected to be “normal” (long wings and red eyes)? What proportion are expected to have dumpy wings and white eyes?

2) A farmer breeds a chicken with all white plumage with a chicken with all black plumage. All of the F1 offspring have bluish-gray plumage. When two of the bluishgray birds are crossed, black, white and bluish-gray offspring are produced. What is the mechanism of inheritance and the genotypes of the parents, F1’s and F2’s.

Explanation / Answer

Here's the dihybrid cross : DDWW × Ddww

DW DW DW DW

Dw DDWw DDWw DDWw DDWw

dw DdWw DdWw DdWw DdWw

Dw repetition of first row

dw repetition of second row.

Therefore we see out of 16 offsprings all of them will be normal. With long wings and red eyes.since only one parent has one recessive gene for dumpy wings ( expression needs both parents to carry recessive genes). And in case of eyes only one parents is homozygous recessive while the other is homozygous dominant.

2) the type of inheritance shown is codominance. Both alleles express themselves therefore the resultant us intermediate between the two just as grey is intermediate between white and black. Genotype of parents are

F1 BB × ww

F2 Bw × Bw

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.