Staph infections, caused by the bacterium staphylococcus aureus, are increasing in frequency and are more difficult to treat with antibiotics. many staph infections are now caused by mrsa, and methicillin-resistant strain of s. aureus. what explains the more widespread phenomenon of mrsa prevalence in staph infections? a) vaccines for mrsa have become not effective because of changes to human immune systems. b) the presence of antibiotics induced the bacterial genomes to mutate and develop resistance to the drug. c) decreased hospital sanitation practices to save money have resulted in increased presence of resistant staph infections. d) selective pressures by excessive antibiotic use have increased the frequency of resistant strains of s. aureus over the last few decades.

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

What processes would you expect to be key in the production of yogurt ?

Easy 6th grade work! 100 points! i need fast! compare the parts of a cell and the cell as a whole to another common nonliving system (i.e., a car, a city, describe the parts of a cell and their primary function.