Question

A pea plant with yellow and round seeds is crossed with another pea plant with green and wrinkled seeds produce 51 yellow round seeds and 49 yellow wrinkled seeds, the genotype of plant with yellow round seeds must be ________
A. YYRr
B. YyRr
C. YyRR
D. YYRR

Answer 1

Hint: When pea plant with yellow and round seeds is crossed with another pea plant with green and wrinkled seeds with the help of punnett square we will find that both the seeds have yellow colour from which half of them are round seeds and rest half have wrinkled seeds as in phenotype.

Complete answer:
When these pea plant of yellow colour and round seeds is crossed with another plant of green colour with wrinkled seeds we observe that the colour of the seed is yellow in both the type of seeds as it is the dominant whereas green colour is recessive, from these about half of them are with round seeds and rest half are wrinkled, so by this result we can conclude that round seeds with yellow colour must be in homozygous form i.e. YY, well then it must heterozygous for round seed type i.e. Rr, so by this we can conclude that the genotype of the plant with yellow round seeds is YYRr. In this we have to note certain things like in seed colour yellow is dominant whereas green is recessive and in seed type round is dominant and wrinkled is recessive.
So, the correct answer is “Option A”.

Note: With the help of punnett square which is a diagram used to determine the genotypes of various cross and breeding experiments, the above genotypes are also the result of this diagram crossing, the punnett square is a visual representation of mendelian inheritance which is important to understand the dominant allele as well as recessive allele.