Question

If two individuals were heterozygous for freckles, which are a dominant autosomal trait, what percentage of their offspring would you expect to have freckles

Answer 1

75%

Step-by-step explanation:

Firstly, an autosomal dominant trait is a trait the becomes expressed in the presence of only one affected allele, which is the dominant allele. Freckles is said to be an autosomal dominant trait meaning that the presence of the dominant allele (F) makes a person have the condition.

According to this question, If two individuals that are heterozygous for freckles cross i.e. Ff × Ff, the following proportion of offsprings will be produced: FF, Ff, Ff and ff (see punnet square).

From the genotypic observation of the produced offsprings:

FF, Ff - possess freckles

ff - do not possess freckles

Since, 3 (FF, Ff and Ff) of 4 offsprings possess freckles, the percentage of offsprings expected to have the condition will be:

3/4 × 100 = 75%