Question

In Mendelian genetics, a pea plant that is heterozygous for seed shape (Rr) and seed color (Yy) is crossed with another plant that has the same genotype.



R represents the dominant allele for round seeds, and r represents the recessive allele for wrinkled seeds.
Y represents the dominant allele for yellow seeds, and y represents the recessive allele for green seeds.
Some offspring show combinations of traits such as round green seeds and wrinkled yellow seeds, even though neither parent shows these trait combinations.



Which statement explains why these traits appear in the offspring according to Mendelian genetics?



A.
Mutations occurred in the alleles of the gametes.

B.
Crossing over exchanged alleles during mitotic cell division.

C.
Independent assortment separated alleles randomly into gametes.

D.
Fertilization randomly sorted alleles so that offspring resembled the parents.

Answer 1

C.

Independent assortment during meiosis separates the R/r and Y/y allele pairs into gametes randomly, producing gametes with all combinations (RY, Ry, rY, ry). When two RrYy parents mate, those gametes can combine to give offspring with new trait combinations (e.g., round green or wrinkled yellow).