Prokaryotes

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A prokaryote is a single celled organism that lacks a true nucleus and other membrane bound organelles.

Structure of Prokaryotic Cell

Characteristics of Prokaryotic Cells:
  1.  Cell is small in size (0.1 - 5 micrometers).
  2. Cell wall is made up of muramic acid (amino acid derivative of peptidoglycan).
  3. In many cells mucopolysaccharide capsule is present.
  4. Mesosomes controls cellular respiration and cell division.
  5. An organised nucleus is absent.
  6. DNA is circular and naked.
  7. Usually polycistronic DNA is present.
  8. Only one kind of RNA polymerase is present.
  9. Transcription and translation both occurs in the cytoplasm.
  10. Extracellular chromosomes are present in the form of plasmid or episome.
  11. Ribosome id 70S (50S + 30S)
  12. Cytoplasm lack cell organelles.
  13. If flagella is present, it is made up of single stranded protein called flagellin.
  14. Microfilaments - Actin and myosin are absent.
  15. Sap vacuoles are absent instead they have gas vacuoles.
  16. Endocytosis and exocytosis are absent.
  17. They divide by amitosis or simple fission.
Examples: Bacteria, Blue-Green Algae, Mycoplasma etc.

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