Phenotype describes which of the following?

• A. Genetic makeup
• B. The sum of allele frequencies in a population
• C. A diagram used to predict offspring
• D. Physical traits

Answer: (D)

Phenotype is the observable traits of an organism—the characteristics you can see or measure, like height, eye color, flower color, or blood type. These traits come from the organism’s genotype (the actual genetic instructions) and from the environment acting on those instructions, so what you observe is the expressed outcome of those genes in real conditions. That’s why physical traits are the best description of phenotype.

This is different from genetic makeup, which is the genotype—the actual set of alleles an individual carries—but not everything about those genes is directly visible. It’s also not about how often certain alleles occur in a population, which describes allele frequencies, or about diagrams used to predict offspring, which help estimate possible outcomes rather than describe what is actually expressed.