Evolution of Eucaryotic Cell

The profound differences between eucaryotic and procaryotic cells have stimulated much discussion about how the more complex eucaryotic cell arose. Some biologists believe the original ‘protoeucaryote’ was a large, aerobic archaeon or bacterium that formed mitochondria, chloroplasts, and nuclei when it plasma membrane invaginated and enclosed genetic material in a double membrane. Theorganelles could then [...]

Germ Theory Of Disease

The ‘germ theory of disease’ has presented a great stimulus in Microbiology and medicine. Louis Pasteur and Robert Koch (1843 – 1910) were the national heroes. Preventive measures also supported the germ theory. Edward Jenner (1796) introduced vaccination (L . vacce, cow) against small pox, using material from lesions of a similar disease of cattle [...]

Nitrogen Fixation

.    The symbiotic association of cyanobacteria with fungi (lichen), cyanobacteria with bryophytes (Anthoceros), with pteridophytes, (Azolla) with gymnospermes (coralloid root of cycas) and bacteria (Rhizobium, Bradyrhizobiun, zorhizobium, sinorhizobium and mesohizobium etc.) With leguminous plants are under mutual beneficial relationship (symbiosis) in which both the host and bacteria are benefitted. There are number of other angiosperms [...]