Cell
Say it: SEL
A cell is the smallest unit that can carry out all the processes of life, enclosed by a membrane and holding its own genetic material.
Also: cells
Definition
What is a cell?
A cell is the basic structural and working unit of every living organism. Some organisms, such as bacteria and yeasts, consist of a single cell, while a human body contains tens of trillions of them. Every cell is bounded by a plasma membrane, is filled with cytoplasm, carries DNA as its genetic material, and makes its proteins on ribosomes.
Cells come in two broad designs. Prokaryotic cells, found in bacteria and archaea, have no nucleus, and their DNA sits in an open region of the cytoplasm. Eukaryotic cells, found in animals, plants, fungi and protists, keep their DNA inside a nucleus and divide their interior into membrane-bound compartments called organelles. In many-celled organisms, cells of the same kind group into tissues, tissues into organs, and organs into organ systems.
Cell theory, developed in the late 1830s by Matthias Schleiden and Theodor Schwann and extended by Rudolf Virchow, states that all living things are made of cells and that every new cell arises from an existing one. Robert Hooke coined the word in 1665 after seeing the tiny box-like compartments in a slice of cork.
Word parts
Where does the word “cell” come from?
- cell
- small roomLatin cella
Practice it
Where you'll meet it
Quizzes that use it
Articles about it
- What Can You Do With a Biology Degree? Career Paths and the Skills Each One Needs
- FASTA, FASTQ, BAM and VCF: Bioinformatics File Formats Explained
- PCR vs qPCR vs RT-PCR vs Digital PCR: What Each One Measures
- How to Read a Volcano Plot: Fold Change, P-Values and FDR Explained
- Building a Career in Cell and Gene Therapy: From Bench to Patient
- How to Break Into AI Drug Discovery: A Skill Roadmap for the AlphaFold Era
Related
Terms that go with it
- ProkaryoteA prokaryote is a usually single-celled organism, a bacterium or an archaeon, whose cell has no nucleus or other membrane-bound organelles.
- EukaryoteA eukaryote is an organism whose cells keep their DNA inside a membrane-bound nucleus and contain other membrane-bound organelles.
- OrganelleAn organelle is a specialized structure inside a cell, usually wrapped in its own membrane, that carries out a particular job for the cell.
- Cell membraneThe cell membrane is the thin, flexible boundary of lipids and proteins that encloses every cell and controls what enters and leaves it.
- NucleusThe nucleus is the membrane-bound organelle that holds a eukaryotic cell's chromosomes and controls which of its genes are used and when.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- OpenStax Biology 2e, 4.1 Studying Cells
- NHGRI Talking Glossary: Cell
- MedlinePlus Genetics: What is a cell?
Last updated
Spotted a mistake? Tell us and we'll correct it.
Practice Cell Biology
Free cell biology quizzes, with an explanation for every answer.
See the Quizzes