Question

question 5
if two individuals were heterozygous for freckles, which is a dominant trait, what percentage of their progeny would have freckles?
a 25%
b 50%
c 75%
d 100%
e 0%

Explanation:

Step1: Define alleles

Let F represent the dominant allele for freckles and f represent the recessive allele. Heterozygous individuals have the genotype Ff.

Step2: Set up Punnett - square

When two Ff individuals cross, the possible gametes from each parent are F and f. The Punnett - square has 4 possible combinations: FF, Ff, Ff, and ff.

Step3: Determine genotypes for freckles

Since freckles is a dominant trait, individuals with genotypes FF and Ff will have freckles. Out of the 4 possible genotypes from the cross (FF:Ff:Ff:ff), 3 genotypes (FF, Ff, Ff) result in freckles.

Step4: Calculate percentage

The percentage of progeny with freckles is $\frac{3}{4}\times100\% = 75\%$.

Answer:

C. 75%