Prokaryotic cells
Nucleus: no distinct nucleus
Chromatin material;The genetic material (DNA) is without any nuclear membrane and freely present in the cytoplasm.
Chromosome; Chromosome is formed of DNA only.
Organelles; Few organelles, None are surrounded by an envelope (two membranes) internal membrane scarce if present usually associated with respiration or photosynthesis.
Ribosomes; Ribosomes are 70 S smaller subunit is 30S while larger subunit is 50 S.
Cell wall; Cell wall is composed of peptidoglycan or murein. When polysaccharide chains are bound covalently to shorter chains of amino acids. Peptidoglycan is formed. The entire cell wall is considered as a single complex molecule called sacculus.
Cell division In prokaryotes mitosis is missing and the cell divided by binary fission.
Organisms; Organisms possessing prokaryotic cells are called prokaryotes
Origin/Evaluation; Prokaryotes are present primitive stage of evaluation.
Flagella; Simple, lacking microtubules extracellular (not enclosed by cell surface membrane) 20 nm diameter.
Respiration; Mesosomes in bacteria except cytoplasmic membrane in blue green algae.
Photosynthesis; No chloroplasts no membrane stacking
Nitrogen fixation; some bacteria
Form; Mainly unicellular
Cell size; Average diameter 0.5 – 20 µm
Examples; Prokaryotes include bacteria and blue green algae (cyanobacteria).
Eukaryotic cells
Nucleus: True nucleus
Chromatin material; A nucleus is present in which nuclear material (chromosomes) is enclosed in double nuclear membrane.
Chromosome; Chromosome is formed of DNA and protein.
Organelles; Many organelles envelop-bound organelles present e.g. nucleus, mitochondria, and chloroplasts. Great diversity of organelles bounded by single membrane e.g. lysosomes, vacuoles, micro bodies, endoplasmic, reticulum etc.
Ribosomes; Ribosomes are 80 S smaller subunit is 40 S while larger subunit is 60 S.
Cell wall; The cell wall, if present is formed of cellulose in most of the plant cells and is formed of chitin in fungi.
Cell division; Cell division by mitosis.
Organisms; Organism possessing eukaryotic cells is called eukaryotes.
Origin/Evaluation; Eukaryotes probably evolved from prokaryotes.
Flagella; Complex structures, with 9 + 2 arrangement of microtubules intracellular (surrounded by cell surface membrane) 200 nm diameter
Respiration; Mitochondria for aerobic respiration.
Photosynthesis; Chloroplasts containing membranes which are usually stacked into lamellae or grana.
Nitrogen fixation; Mainly have the ability.
Form; Mainly multi-cellular (except prototista, many of which are unicellular
Cell size; 10-100 µm diameter common commonly 1000-10000 times volume of prokaryotic cells.
Examples; Eukaryotes include all other unicellular or multi-cellular organisms such as animals, plants fungi and protista.
