Answer to Question #67369 in Molecular Biology for Stefan

Question

Hi

I have to ask you one qustions that I dont quite understand. What is the number of alleles at each locus approximately and how many are there in the human genome? Does it have to do something with chromosome nuber?

Thank you in advance

Answer 1

Locus is the position of gene on chromosome. As there are two chromosomes, there are two alleles per locus.
Each chromosome has multiple loci, and if there are more chromosomes, the number of loci is likely to be higher. However, some chromosomes may be larger and others are smaller, thus, the number of chromosomes does not tell the number of loci.
Human genome encodes for about 19000-20000 proteins. Thus, it has 19000-20000 loci, because each locus on chromosome corresponds to the certain gene, which encodes for protein.