In: Biology
Prokaryotic cells
Prokaryotic cells have naked genetic material in their cells, These type of cells are found in the bacterial and archeal members. Some characters of prokaryotic cells are,
.cells have 0.1 to 5.0 micrometer diameter, smaller than eukaryotic cells.
. Have a peptidoglycan cell wall and polysaccharide capsule in cells. Cell wall help to maintain shape and also gives protection.
. Some of them contain Pili, flagella or fimbriae. Flagella is used for locomotion; Pili is used for the exchange of genetic material , help in conjugation. Fimbriae help in attachment.
. Prokaryotic cell lack a well organised nucleus. The genetic material is seen naked in the cytoplasm. The prokaryotic DNA is known as nucleoid , is seen at the center of the cell.
. Donot have membrane bound organeles as in eukaryotes.
. Plasma membrane is made up of phospholipids.
. Presence of small ribosomes in the cytoplasm. Prokaryotic ribosomes are of 70 S type and are found iin the cytoplasm of cell.
. Prokaryotic DNA interact with Nucleoid associated proteins (NAPs) that help in organisation and packaging of chromosomes. NAPs are similar in function to histones, which are present in eukaryotic cells.
. Prokaryotic cells also contain extra chromosomal DNA , Plasmid . These are circular, small extra chromosomal DNA . Plasmids carry certain genes which shows antibiotic resistance in bacteria.
Some produce Endospores. Endospores help to protect the bacterial genome in dormant state when the environmental conditions are not favourable.
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