What is Molecular Genetics?

Molecular genetics involves studying chromosomes, deoxyribonucleic acid (DNA), and genes, as well as the interactions among three major molecules: DNA, ribonucleic acid (RNA), and protein.  


Human Cells   

Every nucleus of a human cell contains 46 chromosomes arranged in 23 pairs, 22 autosomes, and two sex chromosomes.   


A chromosome is a long strand of supercoiled DNA bonded with protein molecules called histones. Chromosomes contain genes, the unique sequences that code for specific proteins.  

Genes account for a minority of a chromosome’s DNA. Of the remaining DNA, some corrects replication at chromosome termini (telomeres) or regulates movement of chromosomes into daughter cells following cell division (centromeres), but the majority has no known function.  

DNA Molecules  

The DNA molecule consists of two coiled DNA chains that form a double helix.  Each DNA strand has a backbone of 5-carbon sugar (deoxyribose) residues, which are linked by covalent phosphodiester bonds. 

On each residue is a nitrogenous base—either a pyrimidine (cytosine [C] or thymine [T]) or a purine (adenine [A] or guanine [G]).  

The DNA chains have a polarity determine by the orientation of the sugar-phosphate backbone. 

Affiliated Faculty

Alexander Hoffmann

Alexander Hoffmann, PhD

Thomas M. Asher Professor and Director of the Institute for Quantitative and Computational Biosciences (QCBio)
April D Pyle

April D. Pyle, PhD

Professor and Vice Chair of Undergraduate Education and George and Nouhad Ayoub Centennial Chair in Life Sciences Innovation
Stephen T Smale

Stephen T Smale, PhD

Sherie L. Morrison Chair in Microbiology, Immunology and Molecular Genetics and Distinguished Professor

Affiliated Emeritus Faculty