Question

Suppose that allele D produces tiny ears and allele d produces normal ears. A heterozygous male with the Dd genotype mates with a homozygous female with the dd genotype. Tiny ears is an autosomal dominant trait expressed with 70% penetrance. Determine the probability that their offspring will have tiny ears. Report your answer as a percentage without decimal points.

Answer 1

Answer:

The correct answer is 35 percent.

Explanation:

Allele D produced tiny ears, and allele d produces normal ones. If a heterozygous male with Dd mates with the homozygous female with dd, then generally, the expected offspring produced will be 50 percent with tiny ears, and 50 percent with normal ears.  

However, in the given case, the penetrance is 70 percent. Thus, the probability of the offspring with tiny ears will be:  

Penetrance = 70 %

Probability = 70 % of 50 % of 100

= 70/100 * 50/100 * 100

= 35 %

Hence, the probability of the offspring with tiny ears is 35%.