Cell | Definition, Types, Functions, Diagram, Division, Theory,
2025年1月6日 · A cell, in biology, is the basic membrane-bound unit that contains the fundamental molecules of life and of which all living things are composed. A single cell may be …
Structure and types of cells | Britannica - Encyclopedia Britannica
cell, In biology, the basic unit of which all living things are composed; the smallest structural unit of living matter that is able to function independently. A single cell can be a complete organism in …
cell - Kids | Britannica Kids | Homework Help
Most cells have three main parts—the cell membrane, the cytoplasm, and the nucleus. The cell membrane is like the skin of the cell. The cytoplasm performs many functions to keep the cell …
What is a cell? | Britannica - Encyclopedia Britannica
A cell is a mass of cytoplasm that is bound externally by a cell membrane. Usually microscopic in size, cells are the smallest structural units of living matter and compose all living things. Most …
cell - Students | Britannica Kids | Homework Help
The smallest unit of living matter that can exist by itself is the cell. Some organisms, such as bacteria, consist of only a single cell. Others, such as large animals and…
Prokaryote | Definition, Example, & Facts | Britannica
The prokaryotic cell membrane is made up of phospholipids and constitutes the cell’s primary osmotic barrier. The cytoplasm contains ribosomes, which carry out protein synthesis , and a …
Plant cell | Definition, Characteristics, & Diagram | Britannica
A plant cell is the basic unit of all plants. Plant cells, like animal cells, are eukaryotic, meaning they have a membrane-bound nucleus and organelles. Their characteristic cell wall is …
Death - Cell Death, Apoptosis, Necrosis | Britannica
2025年1月18日 · Death - Cell Death, Apoptosis, Necrosis: A vast amount of work has been devoted since the late 19th century to discovering how cells multiply. The study of how and …
Cell Death, Cytology & Signaling Pathways - Britannica
2024年12月12日 · Apoptosis, in biology, a mechanism that allows cells to self-destruct when stimulated by the appropriate trigger. Apoptosis can be triggered by mild cellular injury and by …
prokaryote - Students | Britannica Kids | Homework Help
The prokaryotic cell membrane is made up of phospholipids and constitutes the cell’s primary barrier to the environment. The cytoplasm contains ribosomes, which carry out protein …