Cell key concept "biology"
Cell- it is a structural and functional unit of life is called cell. Cells may be compared to bricks. Bricks are assembled to make a building.Similarly, cells are assembled to make the body of every organism. Robert Hooke in 1665 observed slices of cork under a simple magnifying device. The egg of a hen represents a single cell and is big enough to be seen by the unaided eye. Scientist use microscopes which magnify objects. Stains (dyes) are used to colour parts of the cell to study the detailed structure. Human body has trillions of cells which vary in shapes and sizes. Different groups of cells perform a variety of functions. That combination of cell is called tissue Organisms made of more than one cell are called multicellular. ex-man, cat, dog etc. The single-celled organisms are called unicellular. Ex- ameba, paramecium etc. A single-celled organism, like amoeba, captures and digests food, respires, excretes, grows and reproduces. Similar func
