Library · Genetics
DNA
Make it clearer
DNA is a very long molecule, made of pieces linked one after another called nucleotides. Each nucleotide carries one of four chemical bases, and what matters is not the individual piece but the order they come in: just as the same letters spell different things depending on how you arrange them, the sequence of those bases is what holds information, and that information can pass from one generation to the next.
The cell reads that order and uses it to make RNA, and in many genes that step ends in a protein. It helps not to jumble three words that often get used as if they meant the same thing: DNA is the molecule, a gene is a stretch of DNA with a job of its own, and a chromosome is DNA packed and stored away, like an enormously long cord coiled up so it will fit.
In brief
DNA is a long molecule built from units called nucleotides, each of which carries one of four chemical bases. The sequence of those units stores information that can be inherited.
The order of its bases encodes information that the cell uses to make RNA and, for many genes, proteins.
DNA, genes, and chromosomes are not synonyms: a gene is a functional region of DNA, while a chromosome contains DNA in packaged form.
Sources (2)
- National Human Genome Research InstituteDeoxyribonucleic Acid (DNA) Fact Sheet
- National Human Genome Research InstituteA Brief Guide to Genomics
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated Sources checked by automated review on