Genes involved in the production of abnormal red blood cells have an abnormal sequence of

Genes involved in production of abnormal red blood cells may have an abnormal sequence of bases (nucleotides), like inherited alteration in the gene for JAK2, a protein with enzymatic activity that's linked to the abnormal production of blood cells.

Interacting group of various species in a common location. for example, a forest of trees and undergrowth plants, inhabited by animals and rooted in soil containing bacteria and fungi, constitutes a biological community.