homozygous for white feathers (recessive). according to the punnett square for this cross, what percentage…
homozygous for white feathers (recessive). 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
Explanation:
Step1: Define alleles
Let B represent the dominant allele for blue feathers and b represent the recessive allele for white feathers. The white - feathered bird is homozygous recessive (bb). Assume the blue - feathered bird is heterozygous (Bb) for a simple cross example.
Step2: Set up Punnett square
The possible gametes from the white - feathered bird (bb) are b and b. The possible gametes from the blue - feathered bird (Bb) are B and b. The Punnett square will have two rows and two columns. The top row will have B and b (gametes of the blue - feathered bird) and the left - hand column will have b and b (gametes of the white - feathered bird).
Step3: Fill in Punnett square
When we fill in the Punnett square:
| B | b | |
|---|---|---|
| b | Bb | bb |
| b | Bb | bb |
| We get 2 Bb (blue - feathered) and 2 bb (white - feathered) out of 4 offspring. |
Step4: Calculate percentage
The proportion of blue - feathered offspring (Bb) is $\frac{2}{4}=0.5$ or 50%.
Answer:
50 percent