Some organisms have billions and trillions of cells in a living organism Like Human Beings, Dog, Cat
They are called multi cellular organism
However, there are some organisms which have only one cell Like Bacteria
They are called unicellular or single celled organisms
Difference between multicellular and unicellular organisms
|
Unicellular |
Multicellular |
|
They have only one cell All the functions are performed by a single cell Example - Amoeba and Paramecium |
They have multiple cells Different cells perform different functions Example Human,Animal and Plants |
Basic Structure of Multicellular Organisms
Cells
Multicellular organisms are made of trillions of cells
Tissues
A group of cells work together to perform same function which is called tissues
Example
Muscle tissue,Nervous tissue etc
Organs
Group of tissues combine to form organs
Example - Lungs,Brain ,Kidney are organs
These organs perform different functions(called organ systems)
Example - Stomach ,intestine etc perform digestive function
Organisms
Different Organs combine to form organisms
Example - Human Beings, Dog, Cats, Plants are organisms
Note
In Unicellular organisms, all these functions are performed by single cell
Questions
NCERT Question 1 (a) - Indicate whether the following statements are True (T) or False (F).
Unicellular organisms have one-celled body. (T/F)
