The most fundamental unit of life is cell. Without it there will be no any life forms.
The first cell was discovered from a thin cut portion of cork by Robert Hooke but it was a cell wall which was dead.
The 1st person to observe living cell's is Anton Von Leeuwenhoek.
The cell theory given by Matthias Scleiden and Theodore Schwann can be understand as cells are the constituents of all living organisms. Also new cells arises from the existing old cells.
Cells can be divided as prokaryotic and eukaryotic cell.
Presence of membrane in a cell is called eukaryotic cell whereas prokaryotic cell is the cell lacking membrane.
Eukaryotic cell consists Endoplasmic Reticulum, Golgi Bodies, Mitochondria, etc but prokaryotic cell lacks all these cell organelles.
There is a non membrane organelle which can found in both kinds of cell's. This is Ribosome.
It is very important to note that centrioles are also non-membrane bound organelles but it is found only in animals and is absent in plants.
