Level of life
DNA
The molecule that stores the genetic instructions of all cellular life: two strands wound into a double helix and held together by base pairs.
Gene
A basic unit of heredity: a stretch of DNA with instructions for a product such as a protein or a functional RNA.Source: MedlinePlus
Step 1 of 7ReadingLevel of life
How Gene connects
Gene is found in
Structure
Chromosome
A single DNA molecule packaged with proteins. Human cells usually carry 23 pairs, 46 chromosomes in all.
Idea or model
Human genome
The full DNA sequence of a human. Drafts were published in 2001, and the first gap-free sequence in 2022.
Gene is transcribed into
Level of life
RNA
A single-stranded relative of DNA. Messenger RNA carries a gene's instructions to ribosomes, and other RNAs help build proteins and control genes.
Molecule
Messenger RNA
A copy of a gene's instructions that carries them from DNA to the ribosomes, where proteins are made.
Gene is used by
Process
Transcription
Copying the DNA sequence of a gene into RNA.
Gene is related to
Idea or model
Allele
One of two or more versions of a DNA sequence at the same place in the genome. You inherit one from each parent.
Explore further
Your progress
Sources & further reading
The explanations on this page are our own summaries of these sources. Follow a link to read the original; if anything here disagrees with it, the original wins. How we choose and check sources.
What is a gene? (opens the original in a new tab)
MedlinePlus Genetics. MedlinePlus Genetics. U.S. National Library of Medicine, NIH.
ReferenceGovernment sourceEducational