Question

what is an organism with two of the same alleles of a gene for a trait called?
a homozygous
b heterozygous
c hybrid

Explanation:

To solve this, we recall the definitions:

• Homozygous (option a): An organism with two identical alleles for a gene (e.g., \( AA \) or \( aa \)).
• Heterozygous (option b): Has two different alleles (e.g., \( Aa \)).
• Hybrid (option c): Often refers to offspring of two different species/breeds, not specifically about allele identity.

The question asks for an organism with two of the same alleles, so the correct term is homozygous.

Answer:

a. homozygous