Robotics

Researchers create nano-bot to probe inside human cells

University of Toronto Engineering researchers have built a set of magnetic 'tweezers' that can position a nano-scale bead inside a human cell in three dimensions with unprecedented precision. The nano-bot has already been ...

Energy & Green Tech

How long until efficient fuel cells? Ask the experts

In the quest for the perfect alternative for gas-powered vehicles, there have been a lot of contenders over the years. When it comes to public perception, battery electric vehicles (BEVs) are some of the most widely known. ...

Robotics

New cell-sized micro robots might make incredible journeys

Researchers have harnessed the latest nanofabrication techniques to create bug-shaped robots that are wirelessly powered, able to walk, able to survive harsh environments and tiny enough to be injected through an ordinary ...

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 ...

Engineering

Researchers invent a needle that knows where to go

Syringes and hollow needles have been used to deliver medication for more than a century. However, the precise implementation of these devices depends on the operator, and it can be difficult to deliver medication to delicate ...

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 ...

Energy & Green Tech

Researchers chart path to cheaper flexible solar cells

There's a lot to like about perovskite-based solar cells. They are simple and cheap to produce, offer flexibility that could unlock a wide new range of installation methods and places, and in recent years have reached energy ...

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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