Question

Two pure breeds of pea plant, one with yellow colour seeds (Y) and other with green colour seeds (y) are crossed to obtain $F_1$ generation. The genotypic ratio for the resulting ${F_2}^{}$ generation will be:

• A. 3:1
• B. 1:3:1
• C. 1:2:1
• D. 9:3:3:1

Answer 1

The correct option is C 1:2:1

$\bullet$ Genotype of parents wil be YY and yy since they are pure breeds (homozygous).
$\bullet$ The $F_1$ generation will have all heterozygous progenies (Yy).
$\bullet$ Upon self pollination, in $F_2$ generation, the possible genotypes of seeds will be:

• YY (1) - Homozygous yellow
• Yy (2) - Heterozygous yellow
• yy (1) - Homozygous green

Therefore, the genotypic ratio of $F_2$generation will be 1:2:1.