Question

. In fruit flies, normal wings are dominant and short wings are recessive. Construct a Punnett square wherein both parents are heterozygous for normal wings. Which of the following is the correct genotypic ratio for the F1 generation of this cross?

25% of the offspring are homozygous for normal wings. 50% of the offspring are heterozygous for normal wings. 25% of the offspring are homozygous recessive for short wings.
75% of the offspring have normal wings, and 25% of the offspring have short wings.
50% of the offspring are heterozygous for normal wings. 50% of the offspring are homozygous recessive for short wings.
75% of the offspring are heterozygous for normal wings. 25% of the offspring are homozygous recessive for short wings.

Answer 1

Normal wings = WW
Short wings = ww

The Parents = Ww x Ww

A. 25% are homozygous dominate, 50% are heterozygous, 25% are homozygous recessive.

Answer 2

25% of the offspring are homozygous for normal wings. 50% of the offspring are heterozygous for normal wings. 25% of the offspring are homozygous recessive for short wings.

Step-by-step explanation:

Let dominant allele be A and recessive allele be a

Parent 1: heterozygous normal wings = Aa

Parent 2: heterozygous normal wings = Aa

Parent 1 X Parent 2 :

A a

A AA Aa

a Aa aa

Genotype of progeny will be as follows:

1/4 or 25% = AA = homozygous dominant for normal wings

1/2 or 50% = Aa = heterozygous normal wings

1/4 or 25% = aa = homozygous recessive for short wings