The term for an organism’s genetic makeup is called its genotype. The genotype encompasses all the genes and alleles present in an organism, influencing its physical appearance, behavior, and other traits. This is distinct from the organism's phenotype, which refers to the observable characteristics resulting from the interaction of the genotype with the environment. Understanding genotype is crucial for fields like genetics, evolutionary biology, and medicine, as it helps determine inheritance patterns, genetic disorders, and potential adaptations to environmental changes.