Question

purple petal color in pea plants is dominant to white petal color. two heterozygous pea plants are crossed. what is the ratio of the offspring with white petals to the total number of offspring? express this in a percentage.

Explanation:

Step1: Set up the Punnett - square

Let the dominant allele for purple petals be \(D\) and the recessive allele for white petals be \(d\). The parents are both heterozygous (\(Dd\)). The possible gametes from each parent are \(D\) and \(d\). When we set up the Punnett - square, we have:

	D	d
d	Dd	dd

Step2: Determine the genotypes of offspring

From the Punnett - square, the genotypes of the offspring are \(DD:Dd:dd = 1:2:1\). The \(dd\) genotype results in white - petaled plants.

Step3: Calculate the ratio

The number of offspring with white petals (\(dd\)) is 1, and the total number of offspring is 4. So the ratio of white - petaled offspring to the total number of offspring is \(1:4\).

Step4: Convert to percentage

To convert the ratio \(1:4\) to a percentage, we use the formula \(\frac{1}{4}\times100\%\). \(\frac{1}{4}\times100\% = 25\%\)

Answer:

1:4
25%