Short notes and key points of class 9 biology chapter-Cell

Short notes and key points of class 9 biology chapter-Cell

May 13, 2022, 16:45 IST

Class-9 biology chapter-Cell

The term 'cell' was coined by Robert Hooke in 1665 in his book Micrographia after examining thin slices of cork under a self-designed primitive microscope.

Anton von Leeuwenhoek described free cells for the first time in 1674. Robert Brown in 1831 discovered nucleus, the most important component of every cell. By this time, it had also been known that the cells were surrounded by some sort of limiting membrane .

Cell Theory

Schleiden (1838) and Schwann (1839) gave the 'cell theory’.

The cell the​ory is as follows

1. All organisms are composed of cell and cell products.
2. All metabolic reactions take place in cells. Thus, cells are structural and functional unit of life
3. All cells arise from pre-existing cells only
4. Every organism start its life as a single cell.

• Haeckel (1866) reported that nucleus stores and transmits heredity information
• Discovery of electron microscope in 1940 made it possible to study complex structure of the cell and its organelles.

NCERT solutions for class 9 Science is prepared by Physics Wallah and consist of solution of all questions asked in NCERT Solutions . If any students need to take the online test to check their concepts or undertstanding then they can visit Quiz for Cell .

Download ​Free Pdf sheet of Short notes and key points of Biology for class 9 chapter-Cell from the link given below.