One of two versions of a gene; each gene has two alleles, one coming from each parent.  If the two alleles are the same, they’re “homozygous”.  If the genes are different, they’re “heterozygous”.

Amino Acid

The building block of proteins.   Amino acids carry out many important bodily functions, including giving cells structure.


The basic structural unit that makes up all living things.  The human body is composed of just over 37 trillion cells, most of which contain DNA.  Only red blood cells do not have a nucleus, and therefore, don’t contain DNA.  Cell types vary depending on their location in the body and their function.


Chromosomes are the “packaging” for the DNA found in our cells.  We each have 23 pairs of chromosomes with half coming from our mother, and half from our father for a total of 46.  Human sex is determined by the presence of either a pair of “XX” chromosomes (female) or “XY” chromosomes (male).


A disorder or condition that is often inherited, occurring at or before birth.


Deoxyribonucleic acid or DNA, is the molecule that holds the genetic instructions needed for an organism to develop and function.  Most of our DNA is contained in the nucleus of the cells in our body and forms “sequences” that look like ladders.  These sequences are then converted into messages that can be read to produce amino acids that eventually become the proteins our bodies need to function.

Double Helix

Double helix describes the appearance of double-stranded DNA or what is also known as a DNA ladder.  The “ladder” is made up of two linear strands that run opposite of each other and twist together.  Each DNA strand within the helix or ladder is a long molecule that contains smaller units called nucleotides that form the rungs on the ladder or base pairs.


A portion of DNA responsible for making protein through two processes called transcription and translation.  Genes have the specific information for human traits that are passed down to children from parents.


The study of heredity and the differences in inherited characteristics in living organisms.


The genetic material of an organism or the complete set of genetic material found in each organism. 


A field of science that focuses on the structure, function, evolution, mapping, and editing of genomes.


The genetic makeup of a cell or your complete heritable genetic identity.  It can also refer to a just a particular gene or set of genes unique to you.


The brain of a cell or the membrane bound structure that contains the cell’s hereditary information.   


The units on a DNA molecule, or base pairs, that connect the two DNA helix strands.  There are four types of nucleotides:  adenine (A), cytosine (C), guanine (G) and thymine (T).  Adenine forms a base pair with thymine and cytosine with guanine.


The study of nutrition and energy metabolism related genes.


The study of how genes affect a person’s response to drugs.


A group of large molecules made up of amino acids that perform a number of roles in the human body critical for our survival. 


RNA or ribonucleic acid is the messenger for DNA that gives instructions to a cell to build amino acids, and subsequently proteins. 

Single Nucleotide Polymorphism (SNP)

A SNP (“snip”) is the most common type of genetic variation between humans.  It means that one person will have a certain nucleotide in one position (e.g. A, or adenine) and another person will have a different nucleotide (e.g. C, or cytosine) at that same position.  To be called a SNP, at least 1% of the population must have the nucleotide switch.


A variant is a generic term for any variation in an organism’s genetic sequence. Because a SNP is just one type of variant, this word is frequently used in substitution for the term SNP.