Molecular genetics is the field of biology and genetics that studies the structure and function of genes at a molecular level. Molecular genetics employs the methods of genetics and molecular biology to elucidate molecular function and interactions among genes. It is so called to differentiate it from other sub fields of genetics such as ecological genetics and population genetics.
Along with determining the pattern of descendants, molecular genetics helps in understanding developmental biology, genetic mutations that can cause certain types of diseases. Through utilizing the methods of genetics and molecular biology, molecular genetics discovers the reasons why traits are carried on and how and why some may mutate.
The Y chromosome is one of two sex-determining chromosomes (allosomes) in mammals, including humans (the other is the X chromosome). In mammals, the Y chromosome contains the gene SRY, which triggers testicle development if present. The human Y chromosome is composed of about 50 million base pairs. DNA in the Y chromosome is passed from father to son, and Y-DNA analysis may thus be used in genealogical research. With a 30% difference between humans and chimpanzees, the Y chromosome is one of the fastest evolving parts of the human genome.