Genetics glossary

Jump to: navigation, search

This is a glossary of terms commonly used in the study of genetics and related disciplines in biology. It is intended as introductory material for novices; for more specific and technical detail, please see the article corresponding to each term. Introductory articles in the field include:

Contents Top · 0–9 · A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


  • Adenine: One of the four nucleotide bases in DNA or RNA; pairs with thymine in DNA or uracil in RNA.
  • Allele: one of multiple alternative forms of a single gene, each of which is a viable DNA sequence occupying a given position, or locus on a chromosome. For example, in humans, one allele of the eye-color gene produces blue eyes and another allele of the eye-color gene produces brown eyes.



  • Chromosome: a molecular "package" for carrying DNA in cells, organized as two double-helical DNA molecules that encode many genes. Some simple organisms have only one chromosome made of circular DNA, while most eukaryotes have multiple chromosomes made of linear DNA.
  • Cytosine: One of the four nucleotide bases in DNA or RNA; pairs with guanine.



  • Gene: A set of segments of nucleic acid that contains the information necessary to produce a functional RNA product in a controlled manner. In living organisms, it is a unit of heredity and typically encoded in DNA. A particular gene can have multiple different forms, or alleles, which are defined by different sequences of DNA.
  • Genetics: the field of biology that studies genes and their inheritance.




  • Nucleotide: one of the four monomers that make up a DNA molecule.