Comparision of Prokaryotoc & Eukaryotic cells

 


             

S.no.	Properties	Prokaryotes	Eukaryotes
1	Phylogenetic group	Bacteria, Archaea	Algae, Fungi, Protozoa, Plants & animals.
2	Size	Generally small, usually <2 um in diameter.	Usually large, 2- >100 um in diameter
	Nuclear structure & Function
3	Nuclear membrane	Absent	Present
4	Nucleolus	Absent	Present
5	DNA	Single molecule generally covalently closed & circular, not complexed with histones(other DNA in plasmids)	Linear, present in several chromosomes, usually complexed with histones.
6	Division	No mitosis.	Mitosis; mitotic apparatus with microtubular spindle
7	Sexual Reproduction	Fragmentary process, unidirectional, no meiosis, usually only portion of genetic complement reassorted.	Regular process; meiosis; reassortment of whole chromosome complement
8	Intron in genes	rare	Common
	Cytoplasmic Structures & Function
9	Cytoplasmic membrane	Usually lacks sterols; hopanoids may be present	Sterols usually present; hopanoids absent
10	Internal membrane	Relatively simple; limited to specific groups	Complex; Endoplasmic reticulum, Golgi apparatus.
11	Ribosomes	70s in size	80s, except for ribosome of mitochondria & chloroplast, which are 70s.
12	Membranous organelles	Absent	Several Present
13	Respiratory system	Part of cytoplasmic membrane; Mitochondria absent	In mitochondria; hydrogenosomes in certain anaerobic species
14	Photosynthetic pigments	In internal membranes or chlorosomes; chloroplast absent.	In chloroplast
15	Cell walls	Present (in most) composed of peptidoglycan (Bacteria), Other polysaccharides, protein, glycoproteins (Archaea).	Present in plants, algae, fungi, usually polysaccharides; absent in animals & most protozoa.
16	Endospores	Present (in some), very heat-resistant	Absent
17	Gas vesicles	Present (in some)	Absent
18	Magnetosomes	Present in some species	Rarely Present
	Forms of motility
19	Flagellar movement	In bacteria flagella composed of a single type of protein arranged in a fiber & anchored into the cell wall & membrane; in Archaea, several flagellin protein may be present; flagella rotate.	Flagella or cilia; do not rotate.
20	Non-flagellar movements	Gliding motility; gas vesicle-mediated.	Cytoplasmic streaming & ameboid movement; gliding motility.
21	Cytoskeleton containing microtubules	Absent	Present; microtubules are present in flagella, cilia, basal bodies, mitotic spindle apparatus, centrioles.