In Mendelian genetics, the physical expression of a trait is referred to as:

In Mendelian genetics, the physical expression of a trait is known as the phenotype. This encompasses the observable characteristics or traits of an organism, such as height, flower color, or seed shape. The phenotype results from the interaction of the organism's genotype—its genetic makeup—and environmental factors.

In contrast, the genotype refers to the specific genetic constitution, including the alleles an organism possesses for a particular gene. The karyotype is a complete set of chromosomes in an organism, typically used to assess chromosomal abnormalities. An allele is one of the different forms of a gene that can exist at a specific locus on a chromosome. Thus, the term that accurately describes the visible characteristics of an organism is the phenotype.