BIOL 1002 Chapter : Test One
Document Summary
Clades: formal group or species linked to a common ancestor. Around 1500 species, current total is 1. 6 million. Both bacteria and archaea are very small, ranging from . 2 to 20 micrometers. Three common shapes of prokaryotes: spherical, rod-like, corkscrew shape. Bacteria have peptidoglycan in their cell walls, archaea do not. There are also difference in the plasma membrane composition, ribosomes, and rna polymerases between the two domains. Difference in transcription and translation also exist between the two. Classification within the prokaryotic domains is based on dna sequences. Gram staining characteristics: gram + (violet) and gram (red) due to peptidoglycan. Motile prokaryotes have flagella, hair-like extensions that can rotate rapidly to propel the organism through its liquid environment. As a tuft at the end of cell. Cilia are short hairs, flagella is one long extension. Protective endospores allow some bacteria to withstand adverse conditions endospores are thickly wrapped particles of genetic material.
