Life sciences pillar · 22 definitions
Life sciences, genomics & molecular biology
Clear, citable definitions of the core concepts of molecular biology and genetics — from DNA, genes and the genome to CRISPR, mRNA and gene expression. Written as a research-standards reference: accurate, structured for quick answers, and strictly non-clinical.
From DNA to protein: the central dogma
The information that builds an organism is written in DNA, a long molecule of four chemical bases arranged in a double helix. A gene is a functional segment of that DNA, and the complete set of DNA in an organism is its genome. Genes are put to work through gene expression: DNA is copied into messenger RNA by transcription, and that mRNA is read by a ribosome during translation to build a protein. This flow — DNA to RNA to protein — is the central dogma of molecular biology.
Reading and editing the code
Modern life science is defined by the ability to read and change genetic information. DNA sequencing determines the exact order of bases, while the polymerase chain reaction (PCR) amplifies specific sequences for study. CRISPR and other gene-editing tools allow precise, targeted changes to DNA, and genetic engineering applies these methods across biotechnology. The data they generate are interpreted with bioinformatics.
Why standards matter here
The life sciences are among the most data-intensive fields in research. Genome sequences, gene-expression measurements and structural data are valuable only if they can be found, understood and reused — which is exactly what research-information standards provide. Treating life-science data as FAIR, depositing it in trusted repositories, and describing it with persistent identifiers and shared vocabularies is what makes genomic and molecular research reproducible. The definitions below are the starting point.
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Life sciences definitions
DNA
What is DNA?
DNA is the molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses, encoded in a sequence of four chemical bases.
Read →Gene
What is a gene?
A gene is the basic physical and functional unit of heredity — a stretch of DNA that contains the instructions for making a functional product, usually a protein, and that can be passed from parents to offspring.
Read →Genome
What is a genome?
A genome is the complete set of genetic material in an organism — all of its DNA, including every gene and the non-coding sequences in between — that carries the full instructions needed to build and maintain that organism.
Read →Genetics
What is genetics?
Genetics is the branch of biology that studies genes, heredity, and variation in living organisms — how traits are passed from one generation to the next and why individuals differ from one another.
Read →Genomics
What is genomics?
Genomics is the study of the complete set of an organism’s DNA — its genome — including how genes interact with each other and the environment, rather than focusing on single genes one at a time.
Read →CRISPR
What is CRISPR?
CRISPR is a genome-editing technology, adapted from a bacterial immune system, that lets researchers make precise, targeted changes to DNA using a guide RNA and a cutting enzyme such as Cas9.
Read →Gene editing
What is gene editing?
Gene editing is a group of technologies that let researchers change an organism’s DNA at precise locations — adding, removing, or altering sequence — to study or modify how genes work.
Read →mRNA
What is mRNA (messenger RNA)?
Messenger RNA (mRNA) is a single-stranded molecule that carries genetic instructions copied from DNA to the ribosome, where they are read to build proteins — the working step that links genes to function.
Read →Gene expression
What is gene expression?
Gene expression is the process by which the information held in a gene is used to make a functional product — usually a protein — turning the instructions in DNA into the molecules that build and run a cell.
Read →Transcription
What is transcription?
Transcription is the first step in expressing a gene: the process by which the DNA sequence of a gene is copied into a complementary strand of RNA by the enzyme RNA polymerase.
Read →Translation
What is translation?
Translation is the step of gene expression in which the genetic code carried by messenger RNA is read at the ribosome to assemble a protein, one amino acid at a time.
Read →Epigenetics
What is epigenetics?
Epigenetics is the study of changes in gene activity that do not involve alterations to the underlying DNA sequence — changes that can switch genes on or off and may be passed on as cells divide.
Read →Enzymes
What is an enzyme?
An enzyme is a biological catalyst, usually a protein, that speeds up a specific chemical reaction in a living organism by lowering the energy needed for the reaction to proceed.
Read →Amino acids
What are amino acids?
Amino acids are the small molecules that link together to form proteins. There are 20 standard amino acids, and the order in which they are joined determines a protein’s structure and function.
Read →Proteins
What is a protein?
A protein is a large molecule built from a chain of amino acids that folds into a specific three-dimensional shape, enabling it to perform a vast range of structural, catalytic, and regulatory roles in living organisms.
Read →Antibodies
What is an antibody?
An antibody is a Y-shaped protein produced by the immune system that recognises and binds to a specific target molecule, called an antigen, with great precision — a property widely exploited as a research reagent.
Read →Stem cells
What are stem cells?
Stem cells are unspecialised cells that can both renew themselves and develop into specialised cell types, making them central to development, tissue maintenance, and a major focus of biological research.
Read →PCR
What is PCR (polymerase chain reaction)?
PCR is a laboratory method that rapidly makes millions of copies of a specific DNA sequence, allowing researchers to amplify a tiny amount of DNA into quantities large enough to study.
Read →Genetic engineering
What is genetic engineering?
Genetic engineering is the deliberate modification of an organism’s genetic material using laboratory techniques — adding, removing, or altering DNA — to give the organism new or changed characteristics.
Read →Biotechnology
What is biotechnology?
Biotechnology is the use of living organisms, cells, or biological systems to develop products and processes — from ancient fermentation to modern genetic engineering and industrial enzymes.
Read →Bioinformatics
What is bioinformatics?
Bioinformatics is the field that develops and applies computational methods to analyse biological data — especially DNA, RNA, and protein sequences — turning vast datasets into biological understanding.
Read →DNA sequencing
What is DNA sequencing?
DNA sequencing is the process of determining the precise order of the four bases — adenine, thymine, guanine, and cytosine — along a strand of DNA, reading the genetic code written in a sample.
Read →Common questions
Life sciences FAQ
What is molecular biology?+
Molecular biology is the branch of biology that studies the molecules of life — particularly DNA, RNA and proteins — and how they store, transmit and express genetic information. It underpins genetics, genomics and biotechnology.
What is the central dogma of molecular biology?+
The central dogma describes the normal flow of genetic information: DNA is transcribed into RNA, and RNA is translated into protein. In short, DNA makes RNA makes protein. It is the framework that connects genes to the molecules that build and run a cell.
What is the difference between genetics and genomics?+
Genetics studies individual genes and how single traits are inherited. Genomics studies an organism's entire genome at once — all of its genes, their regulation and their interactions — using DNA sequencing and computational analysis.
Is this a medical or clinical resource?+
No. These pages are a research-standards and science-education reference that define molecular-biology and genetics concepts. They are not medical advice and do not cover diagnosis, treatment or clinical guidance.
How do these definitions relate to CASRAI standards?+
CASRAI is a research-standards body. The life-science datasets these concepts produce — genome sequences, gene-expression data and more — are governed by research-information standards such as persistent identifiers and FAIR data practices, the same standards layer CASRAI maintains for the wider research ecosystem.
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