Astudent complains that it makes no sense to worry about coliform bacteria in water, since we naturally possess harmless coliforms in our intestines anyway. why do regulatory agencies worry about coliform bacteria in water supplies, then? a. not all coliforms are harmless and symbiotic with human beings and some may carry genes/proteins that can make them dangerous to humans; it is best to keep coliforms out of our drinking water, since it is difficult to identify which ones might be harmless and which ones might be harmful. b. the coliforms in our intestines can sometimes turn harmful, causing intestinal infections; we need to constantly be on guard against this happening; coliforms in water might add to this potential problem. c. regulatory agencies simply need something to do to justify their existence; there is no real danger from coliforms in water supplies. d. regulatory agencies are worried that multiple types of coliforms in water might lead to greater antibiotic resistance in the bacterial populations; they try to keep them out of water to keep antibiotic resistance levels down.

Over the past 60 years, many amphibian species have experienced significant population declines and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

Why does the earth spin slowly, not faster? is it possible to prove it scientifically? can you prove it with math?

What would most likely happen to a unicellular organism if it was exposed to a hypotonic solution for an extended period of time?