Question

which one of the following represents a test cross
A) Ww x WW
B) Ww x Ww
C)Ww x ww
D)WW x WW

Answer 1

The correct answer is C) Ww x ww

Explanation:

• Test Cross refers to a cross in which an individual showing a dominant phenotype (WW or Ww) is crossed with an individual having a homozygous recessive genotype (ww) and showing a recessive phenotype.
• This type of cross is done to test whether the individual showing the dominant phenotype has a  homozygous dominant genotype (WW) or a heterozygous dominant genotype (Ww).
• On crossing with the homozygous recessive individual (ww), a homozygous dominant (WW)  individual will give all dominant phenotype in the F1 generation while a heterozygous dominant individual will give both dominant and recessive phenotype in the ratio of 1 : 1 in the F1 generation.