BIOL 1010 Lecture Notes - Azotobacter, Sulfolobus, Phototroph
Document Summary
It is believed by many biologists that prokaryotes have lived on earth for approximately 3. 5 billion years (almost 1. 5 billion without eukaryotes) In terms of impact and numbers, prokaryotes dominate the biosphere: whitman et al. , 1998 (proc. 95:6578) estimated the number of prokaryotes on earth to be 4-6 x 1030 cells containing 350-550 pg of c(1pg=10^15g) 9 - 14 pg of p: prokaryotes contain the equivalent of 60 - 100 % of the carbon found in all of the plants on earth and 10 fold more n and p than plants. Table 1: the number of prokaryotic cells in different environments on earth (whitman et al, 1998) Terrestrial subsurface (habitats below 8 m) 0. 25 - 2. 5. Number of prokaryotic cells (x 1030: prokaryotic cellular production on earth = 1. 7 x 1030 cells/y, prokaryotes perform a number of functions including decomposers, pathogens, symbionts. 8,000 species have been described - estimated 400,000 to 4,000,000 species.
