THE CELLS...

 Types of cells:- There are two types of cells,

        On the basis of structure,

 1.   Prokaryotic cells:- (pro - before; karyon - nucleus ) :- Modern prokaryotes include bacteria and cyanobacteria,

     A group of photosynthetic prokaryotes that were known as the blue algae.

                         fig :- prokaryotic cel                                # Characteristics of prokaryotes :-   prokaryotes are always unicellular organisms .                                                They're small in size compare to           eukaryotes.                                                                   The size of the cell generally varies from 1- 10 microns.  

      They don't contain true nucleus, and nuclear membrane is absent. Protein DNA, remain diffused in the central part of the cell and remain in direct contact with the cytoplasm.

       The nuclear contents may be concentrated within the cell this region called the nucleoid.

         In prokaryotes,DNA is not associated with protein.

       Mitochondria,Golgi complex,Plastids, Endoplasmic reticulum, Lysosomes, etc are absent in prokaryotes.

      Ribosomes are smaller in prokaryotes as compared to ribosomes in eukaryotes. They're scattered randomly in the cytoplasm.

       A single chromosome is present.