Medical research

Scientists find timekeepers of gut's immune system

As people go through their daily and nightly routines, their digestive tracts follow a routine, too: digesting food and absorbing nutrients during waking hours, and replenishing worn-out cells during sleep. Shift work and ...

Neuroscience

Team discovers surprise contributor to multiple sclerosis

Cells that scientists have largely ignored when studying multiple sclerosis are actually key contributors to MS development, new research from the University of Virginia School of Medicine shows. The discovery suggests new ...

HIV & AIDS

Researchers isolate switch that kills inactive HIV

Using genetic sequencing, University of California San Diego School of Medicine researchers have identified a principal cellular player controlling HIV reproduction in immune cells which, when turned off or deleted, eliminates ...

Medical research

New method visualizes groups of neurons as they compute

Using a fluorescent probe that lights up when brain cells are electrically active, MIT and Boston University researchers have shown that they can image the activity of many neurons at once, in the brains of mice.

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Cell (biology)

The cell is the structural and functional unit of all known living organisms. It is the smallest unit of an organism that is classified as living, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular (consist of a single cell). Other organisms, such as humans, are multicellular. (Humans have an estimated 100 trillion or 1014 cells; a typical cell size is 10 µm; a typical cell mass is 1 nanogram.) The largest known cell is an unfertilized ostrich egg cell.

In 1835 before the final cell theory was developed, a Czech Jan Evangelista Purkyně observed small "granules" while looking at the plant tissue through a microscope. The cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells. All cells come from preexisting cells. Vital functions of an organism occur within cells, and all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.

The word cell comes from the Latin cellula, meaning, a small room. The descriptive name for the smallest living biological structure was chosen by Robert Hooke in a book he published in 1665 when he compared the cork cells he saw through his microscope to the small rooms monks lived in.

This text uses material from Wikipedia, licensed under CC BY-SA