Classification of Organisms

Last updated at April 16, 2024 by Teachoo

Unicellular Vs Multicellular Organisms

As the name suggests, Unicellular organisms are one celled organisms.

Multicellular organisms have multiple cells that have various different functions .

Unicellular Organism	Multicellular organism
Has only one cell that performs all body functions	Have multiple cells to perform different body functions
Complete Cell body is in contact with the external environment	Only outer cells of the organism are in contact with the external environment
Usually have short lifespan	Have longer lifespan
Injury leads to death of the organism	Injury to one cell does not lead to death of the organism.
Reproduce mainly asexually	Reproduce sexually as well as asexually
For Example - Bacteria , Yeast etc	For Example - Humans , plants , animals etc

A prokaryotic cell is a unicellular, primitive , simple type of cell characterised by the absence of a nucleus .
Prokaryotes do not have membrane-bound cell organelles .
Since Prokaryotes have no nucleus, their DNA is scattered throughout the cell .
For Example - Bacteria, Archaea
Eukaryotic cells are cells that possess a nucleus .
They have membrane-bound organelles .
The DNA is contained in the nucleus .
Eukaryotes can either be unicellular or multicellular .
For example - Plants , Animals , Fungi etc.

	Prokaryotic Cell	Eukaryotic Cell
Cell Size	*Smaller*	*larger*
Cell Type	*Unicellular*	*Usually multicellular but can be unicellular*
Plasma Membrane	❌	✔️
Endoplasmic Reticulum	❌	✔️
Nucleus	❌	✔️
Chloroplast	❌	✔️ *In plants*
Golgi Apparatus	❌	✔️
Ribosomes	✔️ *smaller*	✔️ *larger*
Mitochondria	✔️	✔️
Examples	*Bacteria*	*Animals and plants*