A locus (plural loci) in genetics is a fixed position on a chromosome, like the position of a gene or a marker (genetic marker). Each chromosome carries many genes; human 's estimated ' haploid ' protein coding genes are 19,000 - 20,000, on the 23 different chromosomes. A variant of the similar DNA sequence located at a given locus is called an allele. The ordered list of loci known for a particular genome is called a gene map. Gene mapping is the process of determining the locus for a particular biological trait.
where is the gene located in the chromosome
A locus