Question

Justify the statement: Cell is the basic unit of life.

Answer 1

Hint: In 1965, Robert Hooke observed slices of cock under microscope. He saw boxes which appeared like honey-comb and coined the term ‘cell’ for each box.

Complete answer:
Cell is the smallest unit of a living organism. A house is made up of many blocks of bricks, thus forming the fundamental structure of the house. Similarly, a living organism is either made up of a single cell (unicellular) or many cells (multicellular). Hence, the cells form the basic structure of any living organism. Every cell in a living organism performs a specific function. Several cells of one kind work collectively to perform specific functions and are known as tissues. Several tissues together form an organ and several organs make up an organ system. Finally, several organ systems function together to form an organism. Hence, the cell is the fundamental and structural basic unit of life.

Additional information:
Generally, cells fall into two major categories: eukaryotes and prokaryotes.
-Prokaryotes are organisms that do not do not contain a membrane-bound nucleus or other membrane-bound organelles. Eg. Bacteria, blue-green algae
-Eukaryotes are organisms that have complex cells in which the genetic material is contained within membrane-bound organelles. Eg. Plants, animals, protozoa, fungi and most algae
-The smallest cell is around 0.1 - 0.5 μm in bacteria whereas the largest cell is the ostrich egg which measures around 17 cm x 130 cm.
-Generally, cells are round, elliptical or rod-like shaped. They vary from organisms to organisms. Some cells have no definite shapes such as amoeba, WBC, etc. Some cells like nerve cells are branched like shapes.

Note: Cells are the basic unit of reproduction. Cell Theory is a universal principle of biology.
There are three basic portions of Cell Theory:
-All organisms consist of one or more cells.
-Cell is the fundamental and structural unit of life.
-Cells arise from pre-existing cells.