Topic 3: Voice of the genome: Cells

HideShow resource information
  • Created by: sia sundu
  • Created on: 10-03-12 20:02

The are 2 types of cells: prokaryotic and eukaryotic.

Prokaryotic cells: Bacteria and cyanobacteria together make up the Prokaryotae Kingdom. Their cells don't have nuclei or other membrane-bound cell organelles. Most prokaryotes are extremely small with diameters between 0.5 and 5 nanometers. Their DNA isn't associated with any proteins and lies free in the cytoplas. A cell wall is always pesent in prokaryotic cells.

The structure of a generalised bacteria cell is: ribosomes, circular DNA, cell surface membrane, cell wall (contains peptidoglycan), cytoplasm, flagellum (hollow cylindrical thread-like structure rotates to move the cell), pili (thin, protein tubes allow bacteria to adhere to surfaces), capsule (slimy layer on surface for protection and to prevent dehydration), plasmid (small circle of DNA), infolding of cell surface membrane (site of respiration).

Eukaryotic cells: all other living organisms have cells that contain discrete membrane-bound organelles. Eukaryotic cells are larger than prokaryotic cells with diameters of 20 nanometers or more.

The structure of a generalised animal cell: mitochondria (the inner…


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all DNA, genetics and evolution resources »