A student encounters a plant bearing small, purple flowers in the wild. The size of the flowers and the purple color are determined by two separate genes. The genes for both small size (S) and purple color (P) are dominant to large size (s) and white color (p), respectively.

Question

A student encounters a plant bearing small, purple flowers in the wild. The size of the flowers and the purple color are determined by two separate genes. The genes for both small size (S) and purple color (P) are dominant to large size (s) and white color (p), respectively.

The student wants to determine the genotype of the newly isolated plant. Crossing it to which of these plants would provide the most information in one generation?
A.
SSPP
B.
SSpp
C.
sspp
D.
SsPp

Answer 1

The most informative cross would be with plant D (SsPp). This is because it contains one copy of each dominant allele (S and P) and one copy of each recessive allele (s and p). By crossing the newly isolated plant with plant D, the student would be able to determine the genotype of the newly isolated plant in one generation based on the phenotypes of the progeny.