Question

Bernard really likes growing peas in his garden, but the peas he likes are green. He also likes them to have a wrinkled texture, because he thinks they look much more interesting that way. Please work out a YyRr x YyRr on another paper while showing all work. 10. After showing your work to use as support, what is the chance that Bernard will have pea plant offspring that match the phenotype he is looking for (green, wrinkled)?

Answer 1

Answer:

3/16

Explanation:

This cross is a typical dihybrid cross involving two different genes; one coding for seed colour and the other for seed texture in pea plant. The allele for green seeds (Y) is dominant over the allele for yellow seed (y) in the first gene while the allele for round seed (R) is dominant over the allele for wrinkled seed (r) in the second gene.

In a cross between two pea plants heterozygous for both genes i.e. YyRr × YyRr, four possible allelic combinations of gametes will be produced by each parent viz;

YyRr- YR, Yr, yR, yr

Using these gametes in a punnet square (see attached image), 16 possible offsprings will be produced in a phenotypic ratio 9:3:3:1.

Bernard is looking for offsprings with green and wrinkled seeds phenotype. The genotype of this can either be; YYrr or Yyrr. Based on the punnet square, only three (3) offsprings will possess such genotypes, hence, the probability of getting a pea offspring with green and wrinked seed is 3/16.