Computer Sciences

Double filters allow for tetrachromatic vision in humans

(Tech Xplore)—A team of researchers at the University of Wisconsin has developed a pair of glasses that allows the wearer to have tetrachromatic vision. In their paper uploaded to the arXiv preprint sever, the group describes ...

Energy & Green Tech

A new water-splitting technique to generate clean hydrogen

Electrolytic hydrogen production entails the generation of hydrogen from water using electrical power, which should ideally come from renewable power sources such as sunlight and wind. Although this method of producing hydrogen ...

Energy & Green Tech

Caffeine gives solar cells an energy boost

Scientists from the University of California, Los Angeles (UCLA) and Solargiga Energy in China have discovered that caffeine can help make a promising alternative to traditional solar cells more efficient at converting light ...

Energy & Green Tech

Improving solar cell efficiency with a bucket of water

Looking at your cell phone, you realize the battery is low, which means you have to make another long walk into town to pay money to charge the device. By the time you get home, it's getting dark. You light the kerosene lamp ...

Energy & Green Tech

New residential solar panels deliver record-breaking efficiency

The solar panels developed by startup Insolight boast an impressive 29 percent yield – a record for the retail market. These systems, which have now been standardized for mass production, contain lenses that focus sunlight ...

Engineering

New hybrid device can both capture and store solar energy

Researchers from the University of Houston have reported a new device that can both efficiently capture solar energy and store it until it is needed, offering promise for applications ranging from power generation to distillation ...

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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