Related topics: cells

Chemists show life on Earth was not a fluke

How life came about from inanimate sets of chemicals is still a mystery. While we may never be certain which chemicals existed on prebiotic Earth, we can study the biomolecules we have today to give us clues about what happened ...

Slow motion waves of jumping genes in the human genome

Nature is full of parasites—organisms that flourish and proliferate at the expense of another species. Surprisingly, these same competing roles of parasite and host can be found in the microscopic molecular world of the ...

Lightning's electromagnetic fields may have protective properties

Lightning was the main electromagnetic presence in the Earth's atmosphere long before the invention of electricity. There are some 2,000 thunderstorms active at any given time, so humans and other organisms have been bathed ...

Self-ventilating workout suit keeps athletes cool and dry

A team of MIT researchers has designed a breathable workout suit with ventilating flaps that open and close in response to an athlete's body heat and sweat. These flaps, which range from thumbnail- to finger-sized, are lined ...

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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.

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