Related topics: proceedings of the national academy of sciences , cancer , cancer cells , stem cells , immune system



Cell (biology)

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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.

For more information about Cell (biology), read the full article at Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.


News tagged with cells

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Scientists isolate new antifreeze molecule in Alaska beetle

Chemistry / Biochemistry

created Dec 14, 2009 | popularity 5 / 5 (13) | comments 4

Scientists have identified a novel antifreeze molecule in a freeze-tolerant Alaska beetle able to survive temperatures below minus 100 degrees Fahrenheit. Unlike all previously described biological antifreezes that contain ...


Scientists use nanosensors for first time to measure cancer biomarkers in blood

Scientists use nanosensors for first time to measure cancer biomarkers in blood

Nanotechnology / Bio & Medicine

created Dec 13, 2009 | popularity 5 / 5 (13) | comments 3

A team led by Yale University researchers has used nanosensors to measure cancer biomarkers in whole blood for the first time. Their findings, which appear December 13 in the advanced online publication of ...


Elusive 'hot' electrons captured in ultra-thin solar cells

Physics / General Physics

created Dec 11, 2009 | popularity 4.5 / 5 (12) | comments 3

Boston College researchers have observed the "hot electron" effect in a solar cell for the first time and successfully harvested the elusive charges using ultra-thin solar cells, opening a potential avenue to improved solar ...


Mechanism discovered by which body's cells encourage tuberculosis infection

Mechanism discovered by which body's cells encourage tuberculosis infection

Medicine & Health / Research

created Dec 10, 2009 | popularity 4 / 5 (1) | comments 0

Scientists have discovered a signaling pathway that tuberculosis bacteria use to coerce disease-fighting cells to switch allegiance and work on their behalf. Epithelial cells line the airways and other surfaces ...


Within a cell, actin keeps things moving

Within a cell, actin keeps things moving

Chemistry / Biochemistry

created 6 hours ago | popularity not rated yet | comments 0

(PhysOrg.com) -- Using new technology developed in his University of Oregon lab, chemist Andrew H. Marcus and his doctoral student Eric N. Senning have captured what they describe as well-orchestrated, actin-driven, ...


Study reveals chemo's toxicity to brain, possible treatment

Medicine & Health / Cancer

created 9 hours ago | popularity 5 / 5 (2) | comments 0

Researchers have developed a novel animal model showing that four commonly used chemotherapy drugs disrupt the birth of new brain cells, and that the condition could be partially reversed with the growth factor IGF-1.


Study reveals lack of diversity in embryonic stem cell lines

Biology / Biotechnology

created Dec 16, 2009 | popularity 5 / 5 (1) | comments 0

The most widely used human embryonic stem cell lines lack genetic diversity, a finding that raises social justice questions that must be addressed to ensure that all sectors of society benefit from stem cell advances, according ...


Researchers find cells move in mysterious ways

Researchers find cells move in mysterious ways (w/ Video)

Biology / Cell & Microbiology

created Dec 16, 2009 | popularity 4 / 5 (2) | comments 0

Our cells are more like us than we may think. They're sensitive to their environment, poking and prodding deliberately at their surroundings with hand-like feelers and chemical signals as they decide whether ...


Stem-cell activators switch function, repress mature cells

Medicine & Health / Research

created Dec 16, 2009 | popularity not rated yet | comments 0

In a developing animal, stem cells proliferate and differentiate to form the organs needed for life. A new study shows how a crucial step in this process happens and how a reversal of that step contributes to cancer.


Scientists use DNA sequencing to attack lung cancer

Medicine & Health / Cancer

created Dec 16, 2009 | popularity 5 / 5 (1) | comments 0

Aided by next-generation DNA sequencing technology, an international team of researchers has gained insights into how more than 60 carcinogens associated with cigarette smoke bind to and chemically modify human DNA, ultimately ...


Marking of tissue-specific crucial in embryonic stem cells to ensure proper function

Biology / Cell & Microbiology

created Dec 16, 2009 | popularity 5 / 5 (1) | comments 0

Tissue-specific genes, thought to be dormant or not marked for activation in embryonic stem cells, are indeed marked by transcription factors, with proper marking potentially crucial for the function of tissues derived from ...


Higher levels of protein hormone associated with lower risk of dementia, Alzheimer's disease

Medicine & Health / Diseases

created Dec 15, 2009 | popularity 5 / 5 (1) | comments 0

Persons with higher levels of leptin, a protein hormone produced by fat cells and involved in the regulation of appetite, may have an associated reduced incidence of Alzheimer disease and dementia, according to a study in ...


Heart cells on lab chip display 'nanosense' that guides behavior

Heart cells on lab chip display 'nanosense' that guides behavior

Nanotechnology / Bio & Medicine

created Dec 15, 2009 | popularity 4 / 5 (2) | comments 1

Johns Hopkins biomedical engineers, working with colleagues in Korea, have produced a laboratory chip with nanoscopic grooves and ridges capable of growing cardiac tissue that more closely resembles natural ...


Biological catch-22 prevents induction of antibodies that block HIV

Medicine & Health / HIV & AIDS

created Dec 15, 2009 | popularity 4.5 / 5 (2) | comments 2

Scientists seeking to understand how to make an AIDS vaccine have found the cause of a major roadblock. It turns out that the immune system can indeed produce cells with the potential to manufacture powerful HIV-blocking ...


Penn researchers find reproductive germ cells survive and thrive in transplants, even among species

Researchers find reproductive germ cells survive and thrive in transplants, even among species

Biology / Cell & Microbiology

created Dec 15, 2009 | popularity 5 / 5 (1) | comments 1

Reproductive researchers from the University of Pennsylvania and The Children's Hospital of Philadelphia have succeeded in isolating and transplanting pure populations of the immature cells that enable male ...