Question

Unattached earlobes are dominant to attached earlobes. Cleft chin is dominant to no cleft. Parents that are heterozygous for both traits are crossed.

Determine the genotype of the following offspring.
1
✔ EeAA

2

3

4
✔ eeAA

5
✔ eeaa
A 4-column table with 4 rows is shown. The columns are labeled Upper E Upper A, Upper E a, e Upper A, e a. The rows are labeled Upper E Upper A, Upper E a, e Upper A, e a. Column 1 has entries Upper E Upper E Upper A uppercase A, 2, Upper E e Upper A Upper A, Upper E e Upper A a. Column 2 has entries Upper E Upper E Upper A a, 3, Upper E e Upper A a, Upper E e a a. Column 3 has entries 1, Upper E e Upper A a, 4, e e Upper A a. Column 4 has entries Upper E e Upper A a, Upper E e a a, e e Upper A a, 5.

Answer 1

Interpret each cell as the product of the row gamete × the column gamete (first allele = E/e, second = A/a). Combining alleles for each locus gives:

1 = EeAA (given)
2 = EEAa
3 = EEaa
4 = eeAA (given)
5 = eeaa (given)

(Phenotypes: E- = unattached earlobes, ee = attached; A- = cleft chin, aa = no cleft.)