Which term best describes the genetic makeup of an organism?

• A. Genotype
• B. Phenotype
• C. Variation
• D. Inheritance

Answer: (A)

Genotype is the genetic makeup because it refers to the specific genes and alleles an organism carries—the internal code inherited from parents. It describes the combination of alleles at each gene locus, which can influence what traits might be produced.

The phenotype, by contrast, is what you can observe in an organism—its outward traits—resulting from the genotype acting in a given environment. Variation means differences among individuals, which can come from different genotypes or environmental factors. Inheritance is about how those genetic traits are passed from parents to offspring.

So, since “genetic makeup” points to the inherited genetic information itself, genotype is the best term.