The Fundamental Units of Life (CBSE IX)

In plant cells, vacuoles are full of cell sap and provide turgidity and rigidity to the cell.

Lysosomes are membrane-bound sacs filled with digestive enzymes.

During endosmosis, water comes out of the cell.

When a living plant cell loses water, plasmolysis occurs.

Because plasma membrane is the outermost layer.

Mitochondria and plastids have their own DNA and Ribosome

Cellulose is a complex substance and provides structural strength to plants.

Cells were discovered by Robert Hooke in 1665 and he saw that the cork resembled the structure of Honey comb. Hence, he called these boxes cells. (Cell is a Latin word, which means a little room.)

Because more water comes into the cell than we leave

The flexibility of the cell membrane enables the cell to engulf the food.

When the cell damaged, lysosomes may burst and the enzyme digest their own cell.

The shape and size of the cell are related to the specific functions they perform.

Cell wall is present only in plant cell.

Mitochondria releases energy in the form of ATP for various activities of the cell.

Schleiden and Schwann proposed the cell theory and they were awarded the Nobel Prize for this contribution.

Plasma membrane is the outer most covering of the cell that separates contents of the cell from external environment.

Plasma membrane is flexible and is made up of organic molecules called lipids and proteins.

Centrosomes are the small region of cytoplasm adjacent to the nucleus.

In 1665, primitive microscopes were available only to Robert Hooke. 

Plastids are present only in plant cells.

The energy required for various process is released in mitochondria.

Animals are dependent for their nutrition and cannot make their own food like plants.

To observe the cells in temporary mounts, all these solutions can be used.

Robert Hooke first observed the cells in cork slice in 1665.