News tagged with cells

Related topics: protein , cancer cells , cancer , stem cells , immune system

Doctor behind 'free radical' aging theory dies

Dr. Denham Harman, a renowned scientist who developed the most widely accepted theory on aging that's now used to study cancer, Alzheimer's disease and other illnesses, has died in Nebraska at age 98.

16 hours ago
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A hybrid vehicle that delivers DNA

A new hybrid vehicle is under development. Its performance isn't measured by the distance it travels, but rather the delivery of its cargo: vaccines that contain genetically engineered DNA to fight HIV, cancer, ...

18 hours ago
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Why cancer cells grow despite a lack of oxygen

Healthy cells reduce their growth when there is a lack of oxygen (hypoxia). This makes it even more surprising that hypoxia is a characteristic feature of malignant tumours. In two publications in the current ...

Nov 25, 2014
popularity 4.8 / 5 (4) | comments 0

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