Plant cells, in addition to the plasma membrane, have another rigid outer covering called the cell wall. The cell wall lies outside the plasma membrane. The plant cell wall is mainly composed of cellulose. Cellulose is a complex substance and provides structural strength to plants.When a living plant cell loses water through osmosis there is …
SIZE OF THE CELLS : There is much variation in size, shape and number of cells in different organisms, and also in various parts of the body. Most of the cells are only a few micrometres in diameter and are visible only with the help of a microscope. SHAPE OF CELLS : Cells may be …
The cell has special components called organelles. How is a cell organised?If we study a cell under a microscope, we would come across three features in almost. every cell; plasma membrane, nucleus and cytoplasm. All activities inside the cell and interactions of the cell with its environment are possible due to these features..
Cells were first discovered by Robert Hooke in 1665. He observed the cells in a cork slice with the help of a primitive microscope.Leeuwenhoek (1674), with the improved microscope, discovered the free living cells in pond water for the first time. It was Robert Brown in 1831 who discovered the nucleus in the cell. Purkinje …
