What is the term for the physical location of a gene on a chromosome?

The term that describes the physical location of a gene on a chromosome is "locus." Each locus is a specific, fixed position on a chromosome where a particular gene is found. Understanding this concept is fundamental in genetics, as it allows researchers and geneticists to determine where specific traits or variations might manifest within an organism's genome.

In genetic terminology, "allele" refers to a specific variant of a gene that may result in different traits, but it does not indicate the physical location of that gene. "Phenotype" describes the observable characteristics or traits of an organism, stemming from the genetic makeup and environmental influences, rather than the gene's location. "Chromatid" refers to one half of a duplicated chromosome, which is not directly related to the specific position of a gene on the chromosome itself.

Thus, the clarity around the term "locus" is essential in understanding genetic mapping and the functioning of genes within the context of heredity and variation.