Differences between Prokaryotic and Eukaryotic cells

Differences between Prokaryotic and Eukaryotic cells



All living organisms can be sorted into one of two groups depending on the fundamental structure of their cells:
  1. The prokaryotes 
  2. The eukaryotes. 
                         Prokaryotes are organisms made up of cells that lack a cell nucleus or any membrane-encased organelles.
                              Eukaryotes are organisms made up of cells that possess a membrane-bound nucleus that holds genetic material as well as membrane-bound organelles.

Definition of eukaryotes and prokaryotes

Prokaryotes (pro-KAR-ee-ot-es) (from Old Greek pro- before + karyon nut or kernel, referring to the cell nucleus, + suffix -otos, pl. -otes; also spelled "procaryotes") are organisms without a cell nucleus (= karyon), or any other membrane-bound organelles. Most are unicellular, but some prokaryotes are multicellular.
Eukaryotes (IPA: [juːˈkæɹɪɒt]) are organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. The most characteristic membrane bound structure is the nucleus. This feature gives them their name, (also spelled "eucaryote,") which comes from the Greek ευ, meaning good/true, and κάρυον, meaning nut, referring to the nucleus. Animals, plants, fungi, and protists are eukaryotes.

 Topics
Prokaryotic
Eukaryotic Cells
Size
Size of cell is 1-2µm by 1-4µm or less
Greater than 5 µm in diameter.
Kind of Cell
Single-cell
Mostly multicellular.
Cell Wall
Cell wall present, comprise of peptidoglycan or mucopeptide (polysaccharide).
Usually cell wall absent, if present (plant cells and fungus), comprises of cellulose (polysaccharide).
 Number of chromosomes
One--but not true chromosome: Plasmids
More than one
 Presence of Nucleus
 Well-defined nucleus is absent, rather 'nucleoid' is present which is an open region containing DNA.
 A well-defined nucleus is present enclosed within nuclear memebrane.
 Shape of DNA
 Circular, double-stranded DNA.
 Linear, double-stranded DNA.
 Mitochondria
 Absent
 Present
 Ribosome
 70s
 80s
 Golgi Apparatus
 Absent
 Present
 Endoplasmic Reticulum
 Absent
 Present
 Mode of Reproduction
 Asexual
 Sexual
 Cell Divison
 Binary Fission,
(conjugation, transformation, transduction)
 Mitosis
 Lysosomes and Peroxisomes
 Absent
 Present
 Chloroplast
 (Absent) scattered in the cytoplasm.
 Present in plant
 Transcription and Translation
 Occurs together
 Transcription occurs in nucleus and translation in cytosol.
 Organelles
 Organelles are not membrane bound, if present any.
 Organelles are membrane bound and are specific in function.
 Replication
 Single origin of replication.
 Multiple origins of replication.
 Examples
 Archaea, Bacteria.
 Plants and Animals.
 Genes
 Expressed in groups called operons.
 Expressed individually.
 Zygote
 Merozygotic (partially diploid).
 Diploid.

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