Question

3. There is a gene that affects pea pod color and has two alleles: G = yellow and g = green. There is another gene that affects pea pod shape and has two alleles: W = round and w = wrinkled. A. Mendel’s original crosses (P generation) would have consisted of what two genotypes? (Hint: this is progeny testing) B. List all of the possible gametes produced by these first or original parent plants. C. If the gametes of question “B” are joined, what will the genotype(s) be in the offspring? D. If the individuals of question “C” are crossed with each other. How many genotypes will be possible in the offspring? E. Give the phenotypic ratios of the offspring produced in question “D” (do not list the phenotypes again here).

Answer 1

The original crosses in Mendel's experiments would consist of parent plants with genotypes GGWW and ggww. The possible gametes and genotypes of the offspring can be determined through Punnett square analysis. The resulting phenotypic ratios would be 9:3:3:1.

Step-by-step explanation:

The original crosses (P generation) in Mendel's experiments would have consisted of two genotypes: one parent plant with yellow pea pods and round shape (genotype GGWW) and another parent plant with green pea pods and wrinkled shape (genotype ggww).

The possible gametes produced by the first parent plant consist of GW and gametes produced by the second parent plant consist of gw.

If the gametes from the first parent (GW) are joined with the gametes from the second parent (gw), the genotype of the offspring will be GgWw.

If the individuals with genotype GgWw are crossed with each other, there will be 9 possible genotypes in the offspring: GGWW, GGWw, GgWW, GgWw, GGww, Ggww, ggWW, ggWw, and ggww.

In terms of phenotypic ratios, the offspring produced from this cross will have a ratio of 9:3:3:1. This means that 9 offspring will have yellow round pods, 3 offspring will have yellow wrinkled pods, 3 offspring will have green round pods, and 1 offspring will have green wrinkled pods.