Question

1. a male with attached earlobes (heterozygous) has children with a female with attached earlobes (heterozygous). what proportion of their children will have attached earlobes? a. 1 of 4 b. 2 of 4 c. 3 of 4 d. 1 of 8 e. none of these are correct

Explanation:

Step1: Set up allele symbols

Let A represent the dominant allele and a represent the recessive allele for earlobe attachment. Both parents are heterozygous (Aa).

Step2: Create a Punnett - square

The possible gametes from each parent are A and a. The Punnett - square has 4 cells: AA, Aa, aA, aa.

Step3: Determine genotypes for attached earlobes

Attached earlobes can be represented by AA, Aa, or aA (since Aa and aA are the same genetically). The genotypes AA, Aa, and aA occur 3 out of 4 times in the Punnett - square.

Answer:

C. 3 of 4