Question

In a genetics lab, your classmate has performed a cross between two inbred lines of fruit flies – one with narrow wings and one with wide wings. She then takes male and female siblings from the resulting progeny and crosses among them. She scores the phenotypes in the resulting progeny from this second round of crosses and finds 302 wide-wing individuals and 98 narrow-wing individuals.

a. How many genes are likely to be involved in determining the observed variation in wing phenotype?

b. How many alleles are likely to be involved in determining the observed variation in wing phenotype?

c. Identify the dominant allele(s).

Answer 1

a. One gene is involved in the wing formation process in frutfly.

b. One gene have two alleles: The allele can be dominant or recessive.

Dominant or recessive conditions can be in homozygous or heterozygous state.

for wing dominant alleles are : WW

recessive alleles :ww

Heterozygous : Ww

c. Here the wild type phenotype is occurd in high number so we can say that wild type phenotype is controlled by dominant allele.

This wild type phenotype can be the result of homozygous dominant or hetrozygous conditions.