Question

in peas, yellow seed color (y) is dominant to green seed color (y). which describes an organism that has nonidentical alleles for seed color?
○ yy and has green seeds
○ yy and has yellow seeds
○ yy and has yellow seeds
○ yy and has green seeds

Explanation:

1. First, recall the concept of alleles: nonidentical alleles mean a heterozygous genotype (one dominant, one recessive allele, like Yy). Identical alleles are homozygous (YY or yy).
2. Analyze each option:

• "yy and has green seeds": yy is homozygous (identical alleles), so eliminate.
• "Yy and has yellow seeds": Yy is heterozygous (nonidentical alleles: Y and y). Since Y is dominant, the phenotype is yellow seeds (dominant allele expresses), which is correct.
• "YY and has yellow seeds": YY is homozygous (identical alleles), eliminate.
• "Yy and has green seeds": Y is dominant, so Yy should express yellow (not green), eliminate.

Answer:

B. Yy and has yellow seeds