A segment of DNA, occupying a specific place on a chromosome, that is the basic unit of heredity. Genes act by directing the production of RNA, which determines the synthesis of proteins that make up living matter and are the catalysts of all cellular processes. The proteins that are determined by genetic DNA result in specific physical traits, such as the shape of a plant leaf, the coloration of an animal's coat, or the texture of a person's hair. Different forms of genes, called alleles, determine how these traits are expressed in a given individual. Humans are thought to have 20,000 to 25,000 genes; bacteria have between 500 and 6,000.
What is a gene? A gene is a sequence of nucleotides along a strand of DNA that a cell nucleus uses to produce proteins. Genes determine the specific traits of an organism. DNA (deoxyribonucleic acid) is a large molecule that is shaped like a double helix sometimes described as a twisty ladder. The rungs of the ladder are made of molecules called nucleotides. These rungs, or bases, are arranged in a specific order that creates a set of instructions, which is known as a gene. When the body needs to do something or build something, it often requires a protein. Genes are the instructions that the cells read for how to build proteins. Proteins have very specific jobs, so scientists name genes based on what job their linked proteins are designed to do. For example, hair proteins come from hair genes, while eye proteins come from eye genes. Every living organism has genes. Animals, plants, fungi, bacteria, and even the humble amoeba all have genes. The more closely related two organisms are, the more similar their genes will be. For example a dog and a wolf, which are from the same genus, will have similar genes, while a dog and a human, which are not part of the same genus, will have much different genes from each other.
First recorded in 1911; from German Gen (1909), apparently abstracted from -gen -gen ( def. ); introduced by Danish geneticist Wilhelm L. Johannsen (1857–1927)
Microscopic, yet powerful, a gene is segment of DNA, the molecule that stores the code for building living bodies. A gene is a single unit of genetic information, stored on twisting strands in every cell of every living being. In sexual reproduction, the parents' genes mix together to make the child. Although people would like to think that genes code for discrete traits, like friendliness or mathematical genius, that's not the case. Genes control the color of your eyes and the shape of your toes, not your weird personality.
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Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
He’s 6 feet 1 and 190 pounds, and definitely possesses the fearless gene the way he attacks defenders when he has the ball.
From Los Angeles Times ● Oct. 31, 2026
One promising application involves developing synthetic molecular sensors and switches that can regulate gene activity.
From Science Daily ● Oct. 31, 2026
Mayo Clinic endocrinologist Sundeep Khosla, M.D., served as senior author of the study, "A new gene set identifies senescent cells and predicts senescence-associated pathways across tissues."
From Science Daily ● Oct. 27, 2026
To help address this challenge, researchers developed a tool called the SenMayo gene set.
From Science Daily ● Oct. 27, 2026
The delayed recognition of the gene as the answer to the central problem of biology had a strange consequence: genetics had to be reconciled with other major fields of biology as an afterthought.
From "The Gene" by Siddhartha Mukherjee
As Jean-Luc Picard, the captain who inherited the helm of USS Enterprise from William Shatner’s James T. Kirk, Stewart embodied franchise founder Gene Roddenberry’s humanist outlook.
From Salon ● Oct. 30, 2026
Undoubtedly, Stewart’s Shakespearean training helped him look past the costumes, sets and CGI into the humanity of what the writers and Gene Roddenberry intended.
From Los Angeles Times ● Oct. 29, 2026
The Roadster demo “was an engineering flex with no commercial value beyond embarrassing traditional car makers,” Gene Munster, managing partner at Deepwater Asset Management, wrote on X.
From MarketWatch ● Oct. 16, 2026
Port of Los Angeles Executive Director Gene Seroka said struggling carriers approached the port to request help earlier this year.
From The Wall Street Journal ● Oct. 8, 2026
For a number of reasons, Gene Park was a likely candidate, and so he decided to examine these loans that AIG FP was insuring a bit more closely.
From "The Big Short" by Michael Lewis
Coupled with abundant haplotype diversity, tetraploid potato may therefore contain thousands of -gene analogues.
From Nature ● Jul. 13, 2011
Jumping genes are pieces of DNA that can move to different locations within a genome and produce additional copies of themselves.
From Science Daily ● Oct. 28, 2026
Inside: dozens of small boxes with barcoded glass tubes, collectively containing one hundred billion genes.
From BBC ● Oct. 28, 2026
To investigate how jumping genes influenced ant evolution, the international research team examined and compared the genomes of 163 ant species.
From Science Daily ● Oct. 28, 2026
The findings suggest that jumping genes may have contributed to the expansion of these sensory systems, potentially improving the ability of ants to detect and interpret the chemical messages that make their complex societies possible.
From Science Daily ● Oct. 28, 2026
Since twins share identical genetic material, he reasoned, any substantial similarities between them could be attributed to genes, while any differences were the consequence of environment.
From "The Gene" by Siddhartha Mukherjee
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