biology notes

  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  ...