Why are single celled organism so small?

Answer 1

There is a limit to how big a cell can get, and that nearly always means we need a microscope to see them, Size is limited by the need for substances to diffuse in and out of the cell. If it gets too big there simply isn't enough surface to allow enough exchange of substances for the cell to maintain its life processes.

Answer 2

Single celled organisms are composed of one cell only. Now a cell is the basis of all organs which are in turn made up of tissue and tissue are ultimately a collection of cells. So single celled organisms are exactly that, they are just cells that perform basic functions.

Answer 3

Because they lack tissues, and they don't have specialized cells.

Answer 4

i think they are because due to single cell having small body structure mostly which r found in the world are micro organisms

Answer 5

Single cell organism are not animals. They are small because... er they are singled celled.

Answer 6

single cell organisms are so small because they have 1 cell

if they were bigger then they are called multi celled organisms not single celled organisms

Answer 7

Because cells are, themselves only visible through a microscope ! Our eyes cannot see objects that small without assistance.