CBSE 2022 · Region 1 · Set 3 · Q11

A red-eyed individual is crossed with a white-eyed individual to produce $\displaystyle \mathrm{F}_{1}$ progeny with red eyes. When $\displaystyle \mathrm{F}_{1}$ individuals are intercrossed, $\displaystyle \mathrm{F}_{2}$ progeny is formed with both red as well as white-eyed individuals.

(a)

How is the dominant trait identified?

(b)

What are recessive traits?

(c)

If $\displaystyle 12$ individuals are produced in $\displaystyle \mathrm{F}_{2}$ generation, then how many white-eyed individuals would be obtained? Calculate the ratio of red-eyed individuals to white-eyed individuals. \[1+\frac{1}{2}+\frac{1}{2}+1 \]