A gene is a segment of DNA that carries the instructions for building a functional product, usually a protein and sometimes an RNA molecule, and is passed from parents to offspring as a basic unit of heredity.

Quick Scoop

Simple definition

  • A gene is a stretch of DNA located on a chromosome that contains coded information for making a specific protein or functional RNA.
  • These instructions help determine traits such as eye color, blood type, or how cells carry out vital functions.

Genes and inheritance

  • Genes are the basic physical and functional units of inheritance, meaning they are passed from parents to children and help explain why relatives resemble each other.
  • Humans have roughly about 20,000 proteinā€‘coding genes, each contributing in small ways to how the body develops and works.

How genes work

  • During gene expression, the DNA sequence of a gene is copied into RNA; that RNA can either be used directly in the cell or used as a template to build a protein.
  • The proteins or RNAs produced from genes carry out most of the structure and chemistry inside cells, from muscle contraction to fighting infections.

Modern view (quick nuance)

  • Classic genetics talks about genes as ā€œunits of heredity,ā€ while modern molecular biology defines a gene more precisely as a DNA sequence that is transcribed to produce a functional RNA product (proteinā€‘coding or nonā€‘coding).
  • Because some genes overlap and share regulatory regions, many researchers now think of a gene as a set of genomic sequences that together produce one or more related functional products.

TL;DR: A gene is a piece of DNA on a chromosome that carries the instructions for making a specific protein or RNA, acting as a fundamental unit of heredity that shapes traits and cell functions.

Information gathered from public forums or data available on the internet and portrayed here.