Last updated on May 16th, 2021
All living cells can be classified as either prokaryotic or eukaryotic. Prokaryotic cells lack a nucleus and other membrane-enclosed structures, whereas eukaryotic cells have such structures.
All prokaryotes are single-celled organisms and all are bacteria. Eukaryotes include all plants, animals, fungi, and protists (such as malaria parasites).
|Features||Procaryotic cells||Eucaryotic cells|
|Size||1-2 by 1-4 micrometer or less||Greater than 5 micrometer in width or diameter|
|Location||Nucleoid, chromatin body or nuclear material||Nucleus, mitochondria, chloroplasts|
|Structure of nucleus||Not bounded by nuclear membrane; one circular chromosome|
Chromosome does not contain histones; no mitotic division
Nucleolus absent; functionally related genes may be clustered.
|Bounded by nuclear membrane; more than one chromosome|
Chromosomes have histones; mitotic nuclear divisionNucelolus present; functionally related genes not clustered
|Sexuality||Zygote nature is merozygotic (partial diploid)||Zygote is diploid|
|Cytoplasmic nature and Structures|
|Gas vacuoles||Can be present||Absent|
|Ribosomes||70S, distributed in the cytoplasm.||80S arrayed on membranes as in endoplasmic reticulum; 70S in mitochondria and chloroplasts|
|Chloroplasts||Absent||May be present|
|Membrane-bound (true) vacuoles||Absent||Present|
|Outer Cell Structure|
|Cytoplasmic membranes||Generally do not contain sterols; contain part of respiratory and, in some, photosynthetic machinery||Sterols present; do not carry out respiration and photosynthesis|
|Cell Wall||Peptidoglycan (murein or mucopeptide) as component||Absence of peptidoglycan|
|Locomotor organelles||Simple fibril (flagella)||Multifibrilled with “9+2” microtubules|
|Pseudopodia||Absent||Present in some|
|Metabolic mechanisms||Wide variety, particularly that of anaerobic energy yielding reactions; some fix nitrogen gas; some accumulate poly-β-hydroxybutyrate as reserve material||Glycolysis is pathway for anaerobic energy-yielding mechanism|
|DNA base ratios as moles % of guanine + cytosine (G+C%)||28 to 73||About 40|