Why is life based upon the cell?

More or less, why are cells necessary for life?

Is there a limit to how large a cell can be?

** If anyone can help or just give me an idea to go on for this it would be helpful! Even a good site to start research!

THANKS!

There may be life elsewhere that is not cellular. On earth it appears to be the only system (other than viruses) Cells are mostly small because they have a large surface area in relation to volume. This allows for sufficient diffusion. Please see:

http://www.tiem.utk.edu/~gross/bioed/bealsmodules/area_volume.html

http://en.wikipedia.org/wiki/Cell_(biology)#Origins_of_cells

The cell is the basic unit of life because it is where all the vital processes necessary for an organism to survive and function occur. Cells are necessary for life because they carry out essential functions such as obtaining energy, reproducing, and maintaining homeostasis.

In terms of why life is based upon cells, it is primarily due to the complex and intricate structures and processes that cells possess. Cells contain all the genetic information necessary for an organism to develop and function. They have specialized compartments, known as organelles, that carry out specific functions, such as mitochondria for energy production and the nucleus for storing genetic material.

Cells also have the ability to interact with their environment, respond to stimuli, and adapt to changes, which are crucial for survival. They carry out processes such as metabolism, growth, and repair.

Regarding the limit to the size of a cell, it is determined by the surface area-to-volume ratio. Cells need a large surface area to efficiently exchange materials with their surroundings, such as nutrients and waste products. As a cell grows, its volume increases faster than its surface area, which can lead to limitations in obtaining resources and removing waste. Thus, there is a practical limit to how large a cell can be, which is why multicellular organisms have evolved.

For further research, you can refer to the provided links for more detailed information on the origins of cells and the relationship between surface area, volume, and cell size.