What do you mean by cell?

Cell is the structural and functional unit of all living organisms.Cells are usually small in size, but there are some exceptions like ostrich egg. Different parts of cell can be viewed under microscope.Cell was discovered by Robert Hooke in 1665.A cell is usually surrounded by a cell membrane. In plant cells, it has an additional layer named cell wall.The three components of the cell are nucleus, cytoplasm and cell membrane.Cells have membranous and non-membranous organelles like nucleus, mitochondria, endoplasmic reticulum, plastids, lysosomes, centrosomes, vacuoles, etc.

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