Question

Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. A parakeet that is heterozygous for blue feathers (dominant) is crossed with a parakeet that is homozygous for white feathers (recessive).

White Bird on the Left and Blue Birrd on the Right

According to the Punnett square for this cross, what percentage of offspring is predicted to have blue feathers?
25 percent
50 percent
75 percent
100 percent

Answer 1

Answer by YourHope:

Hello fellow army~

According to the Punnett square for this cross, what percentage of offspring is predicted to have blue feathers?

The answer is 50% ♡♡♡

^-^

Answer 2

50 percent

Step-by-step explanation:

A single copy of a dominant allele is enough to be expressed, but recessive alleles need two copies to express. For that reason, the possible genotypes and phenotypes for feather colors are:

• BB: blue
• Bb: blue
• bb: white

The parakeet with blue feathers is heterozygous, so it the has both a dominant allele for blue feathers (B) and a recessive allele for white feathers (b) and the genotype is Bb. The other parakeet is homozygous for white feathers, so it has two b alleles and the genotype bb.

When individuals produce gametes, the alleles separate, so the heterozygous parakeet will produce the gametes B and b, and the homozygous parakeet will produce two b gametes.

The Punnett Square shows the possible combination of the gametes produced by the two parents, and therefore the genotypes of the offspring:

• Bb - blue feathers
• Bb - blue feathers
• bb - white feathers
• bb - white feathers

2 out of four individuals of the offpring (50%) will have the genotype Bb and blue feathers.