An organism's genetic makeup, represented by letters, is called:

An organism's genetic makeup, represented by letters, is called:

• A. Genotype
• B. Phenotype
• C. Trait
• D. Chromosome

Answer: (A)

The genetic makeup of an organism—the alleles it carries at its genes—is called genotype. Letters are used to represent these alleles, so combinations like AA, Aa, or aa describe the genotype at a particular gene. The genotype is different from the phenotype, which is the observable traits that result from how those genes are expressed in the body and can be influenced by the environment. A chromosome, while essential for containing genes, is a structure that houses DNA rather than being the complete genetic makeup itself. A trait is any observable characteristic, not the genetic blueprint.

The genetic makeup of an organism—the alleles it carries at its genes—is called genotype. Letters are used to represent these alleles, so combinations like AA, Aa, or aa describe the genotype at a particular gene. The genotype is different from the phenotype, which is the observable traits that result from how those genes are expressed in the body and can be influenced by the environment. A chromosome, while essential for containing genes, is a structure that houses DNA rather than being the complete genetic makeup itself. A trait is any observable characteristic, not the genetic blueprint.