Question

A pea plant with yellow and round seeds (YYRR) is crossed with a pea plant having green and wrinkled (yyrr) seeds, then in $F_2$ generation of this dihybrid cross, 320 plants are produced. Out of which 180 plants have same phenotypic characters. Identify this phenotype.

• A. Yellow and wrinkled seeds
• B. Yellow and round seeds
• C. Green and round seeds
• D. Green and wrinkled seeds

Answer 1

The correct option is B Yellow and round seeds

In a normal cross, we have the phenotypic ratio of 9:3:3:1, where offsprings are:
9 - Yellow round seeds
3 - Green round seeds
3 - Yellow wrinkled seeds
1 - Green wrinkled seeds
In 320 offsprings, 180 offsprings have the same phenotype, this states that these 180 plants have phenotype yellow and round seeds. This can be explained as follows:
$\frac{x}{16}\times 320=180$
$x=\frac{180\times 16}{320}=9$
So, 180 offsprings will have yellow and round seeds.