Question

In humans the dominant attached earlobe phenotype is encoded by the A allele and Widows peak hairline is encoded by W allele. What would be the expected phenotypic ratio for this characteristic in the offspring of an AaWw father and an aaww mother ( AaWw X aaww)?

Answer 1

The expected phenotypic ratio in the offspring of an AaWw father and an aaww mother would be 3:1 for attached earlobes and widows peak hairline.

Step-by-step explanation:

The expected phenotypic ratio for the offspring of an AaWw father and an aaww mother (AaWw X aaww) would be 3:1.

Let's break down the cross:

The father has the genotype AaWw, which means he has one dominant allele for attached earlobes (A) and one recessive allele for widows peak hairline (w).

The mother has the genotype aaww, which means she has two recessive alleles for attached earlobes (aa) and two recessive alleles for widows peak hairline (ww).

When the alleles from the father and mother combine, the possible genotypes of the offspring are: AaWw, Aaww, aaWw, aaww.

Out of these genotypes, the phenotypes can be determined as follows:

AaWw and Aaww would both have attached earlobes and widows peak hairline.

aaWw and aaww would both have attached earlobes and no widows peak hairline.

Therefore, the expected phenotypic ratio is 3 individuals with attached earlobes and widows peak hairline to 1 individual with attached earlobes and no widows peak hairline.