- plasmids are small loops of dna that aren't part of the main circular dna molecule. plasmids contain genes for things like antibiotic resistance, and can be passed between prokaryotes. plasmids are not always present in prokaryotic cells. some prokaryotic cells have several.

- unlike a eukaryotic cell, a prokaryotic cell doesn't have a nucleus. instead, the dna floats free in the cytoplasm. it's circular dna, present as one coiled up strand. it's not attached to any histone proteins.

- the flagellum (plural flagella) is a long, hair-like structure that rotates to make the prokaryotic cell move. not all prokaryotes have a flagellum. some have more than one.

- cytoplasm contains ribosomes; but they're smaller than those in a eukaryotic cell.

- prokaryotic cells are extremely small; less than 2μm in diameter (that's two millionths of a metre or 0.002 mm). eukaryotic cells can be up to 50 times bigger (although still only around 0.1mm).

	Criado por izzy smith mais de 7 anos atrás

A level Biology (topic 2a : cell structure and division) Slides sobre prokaryotic cells and viruses, criado por izzy smith em 13-04-2017.