What is the term for the observable characteristics of an organism?

The observable characteristics of an organism are referred to as the phenotype. This term encompasses all of the visible traits and features, such as coloration, shape, size, and behavior, that result from the interaction of an organism's genetic makeup (genotype) and its environment. The phenotype is what you can see as a result of the genetic information an organism carries, but it also reflects how these genes are expressed in a given environment.

In contrast, genotype refers specifically to the genetic constitution of an organism, indicating which alleles are present. Alleles are different forms of a gene that can exist at a specific locus, while chromosomes are structures within cells that contain DNA; they carry the genes but are not the traits themselves. Therefore, when asked about observable characteristics, phenotype is the term that accurately describes those traits that can be seen or measured.