Question

bb is an example of...
a genotype.
a phenotype.
an allele.
a gene.

Explanation:

• Genotype: It refers to the genetic makeup of an organism. In the case of "Bb", it represents the combination of alleles (B and b) for a particular gene.
• Phenotype: This is the observable physical or biochemical characteristic of an organism, which is determined by the genotype and environmental factors. "Bb" does not describe a physical trait directly.
• Allele: An allele is a variant form of a gene. "B" and "b" are alleles, but "Bb" is a combination of two alleles (not just a single allele).
• Gene: A gene is a segment of DNA that codes for a specific trait. "Bb" is not a gene itself but a combination of alleles for a gene.

Answer:

a genotype.