Question

When single gene produces two effects and one of it is lethal, then the ratio is a) 2:1
b) 1:1
c) 1:2:1 d) 1:1:1:1

Answer 1

the right answer is

2:1

thnx dear

Answer 2

Hii Dhananjay,

◆ Answer -

When single gene produces two effects and one of it is lethal, then the ratio is 2 : 1 .

◆ Lethal genes -

- Genes/alleles that cause the death of the organism that carries them are called lethal genes.

- Usually mutation of essential genes results into lethal genes.

- For example, when two heterozygous yellow mice (Yy) are hybridised with each other, F2 phenotype should be 3:1.

i.e. 3 Yellow (YY, Yy, Yy) & 1 white (yy)

- But as homozygous yellow (YY) is lethal & dont survive. Thus phenotype of F2 is 2:1.

Hope this helped you. Thanks for asking..