unattached earlobes are dominant to attached earlobes. cleft chin is dominant to no cleft. parents that are…

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 ratio of offspring with the described trait to the total number of offspring: unattached earlobes and cleft chin unattached earlobes and no cleft attached earlobes and cleft chin attached earlobes and no cleft

Answer

Explanation:

Step1: Determine the total number of offspring

The Punnett - square has 16 boxes, so the total number of offspring is 16.

Step2: Count offspring with unattached earlobes and cleft chin

Unattached earlobes are dominant (E -) and cleft chin is dominant (A -). Count the genotypes that start with E and A. There are 9 such genotypes (EEAA, EEAa, EeAA, EeAa repeated multiple times), so the ratio is 9:16.

Step3: Count offspring with unattached earlobes and no cleft

Unattached earlobes (E -) and no cleft (aa). The genotypes are Eeaa and EEaa. There are 3 such genotypes, so the ratio is 3:16.

Step4: Count offspring with attached earlobes and cleft chin

Attached earlobes (ee) and cleft chin (A -). The genotypes are eeAA and eeAa. There are 3 such genotypes, so the ratio is 3:16.

Step5: Count offspring with attached earlobes and no cleft

Attached earlobes (ee) and no cleft (aa). The genotype is eea, and there is 1 such genotype, so the ratio is 1:16.

Answer:

Unattached earlobes and cleft chin: 9:16 Unattached earlobes and no cleft: 3:16 Attached earlobes and cleft chin: 3:16 Attached earlobes and no cleft: 1:16