PROKARYOTIC ORGANISMS

 PROKARYOTES

➤DEFINITION ;

★PROKARYOTIC CELLS HAVE NO PROMINENT NUCLEUS AND MEMBRANE

   BOUND ORGANELLES . 

➤DERIVED FROM;

★IT IS DERIVED FROM GREEK WORD PRO MEANS "BEFORE" AND KARYON

   MEANS "NUCLEUS".

➤GENETIC MATERIAL;

★IN PROKARYOTIC CELLS THE GENETIC MATERIAL (DNA) IS WITHOUT ANY

   NUCLEAR MEMBRANE COVERING AND IS DIRECTLY SUBMERGED IN THE

  CYTOPLASM.

➤PROKARYOTES;

★ORGANISMS POSSESSING PROKARYOTIC CELLS CALLED PROKARYOTES.

➤DIVISION OF CELLS;

★IN PROKARYOTES MITOSES IS MISSING AND CELL DIVIDES BY BINARY 

   FISSION.

➤RIBOSOMES;

★PROKARYOTIC CELLS HAVE SMALL SIZED RIBOSOMES "SEDIMENTS AT 

 70S".

➤DISTINCTIVE FEATURE OF PROKARYOTES;

★PERHAPS THE MOST DISTINCTIVE FEATURE OF THE PROKARYOTIC CELL IS

   ITS "CELL WALL" ,COMPOSED OF POLYSACCHARIDE CHAINS BOUND BY

   COVALENTLY TO SHORTER CHAINS OF AMINO ACIDS FORMING

 PEPTIDOGLYCON OR MUREIN.

➤FOR EXAMPLES;

★BACTERIA

★CYANOBACTERIA (BLUE GREEN ALGAE)

★E.COLI (ESCHERICHIA COLI)

★MYCOPLASMA

★ARCHAEA

 GENERALIZED PROKARYOTIC CELL