The dominant allele determines the yellow color of pea seeds, while the recessive allele determines the green color of seeds. The green color of the offspring will appear only if the recessive allele is inherited from both of the parental plants – yy genotype. We can conclude that the yellow pea from the parental generation was heterozygous, while green one was homozygous recessive. The green pea seeds in the F1 generation are also homozygous recessive, which will give only green seeds in the F2 generation. The answer is D.

D

The dominant alleles determine the tallness and the smooth pod, while the recessive alleles determine the shortness and the constricted pod. When a plant inherits one, or two dominant alleles from its parents, that will express the dominant trait. The recessive trait of the offspring will appear only if the recessive allele is inherited from both of the parental plants. As we can see in the table, there are 12 tall and 4 short plants, as well as 12 plants with smooth and 4 with the constricted pod. That is the ratio of 3:1.

A. 3 : 1

Morgan has discovered that certain genes of the same chromosome are inherited together as a group, while those groups of genes are assorted independently. The closer together these groups are, there is a minor chance for a cross-over between them and a greater chance of passing these groups of genes together on to the offspring.

E. black body and light eye because they are closest together on chromosome 2