Question

Complete the Punnett square for the following cross-pollination and give the genotypic and phenotypic ratios: for white (WW) and black (ww) Female: x Male:Ww Male: ww
let the () count as spaces
() () ()
() () ()
() () ()

Answer 1

Answer:

Phenotypic ratio= 1:1

Genotypic ratio = 1:1

Explanation:

This is a monohybrid cross involving a single gene that specifies a color phenotype.

According to the question, WW, which is homozygous dominant i.e same allele is white while ww, which is homozygous recessive is black.

Hence a genotype Ww will possess a white phenotype since the W allele will mask the expression of w.

In a cross between a female and male with a a Genotype Ww and ww respectively. The parents alleles will be separated into gametes according to Mendel's law of segregation. (See attached image).

Ww will produce gametes W and w

ww will produce gametes w and w

The four possible offsprings will have Ww (2) and ww (2) genotypes. Hence two of them will be white while two will be black.

Hence, the phenotypic ratio will be 1:1 while the genotypic ratio will also be 1 Ww: 1 ww