The genetic makeup of an organism.

Here's why:

* Genotype refers to the specific combination of alleles (different versions of a gene) that an organism inherits from its parents. This genetic code determines the organism's potential traits.

* Phenotype refers to the actual observable characteristics of an organism, which are influenced by both the genotype and environmental factors.

Example:

* Genotype: A person might have the genotype "BB" for the gene that determines eye color, meaning they inherited two dominant alleles for brown eyes.

* Phenotype: This person would have brown eyes, as the dominant "B" allele masks the recessive allele.