What did chargaff discover while studying bases in the dna of organisms? the bases in the dna of each organism were unique. the ratios of thymine and adenine were similar, as were the ratios of guanine and cytosine. the overall percentages of bases were different from one organism to the next. there were equal amounts of all four bases in every organism, or 25 percent of each base.

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

Osmosis is often viewed incorrectly as a process driven directly by differences in solute concentration across a selectively permeable membrane. what really drives osmosis? view available hint(s)osmosis is often viewed incorrectly as a process driven directly by differences in solute concentration across a selectively permeable membrane. what really drives osmosis? the first law of thermodynamicsthe difference in the height of water columns on either side of a selectively permeable membranethe difference in water concentration across a selectively permeable membranethe difference in sugar or ion concentration across a selectively permeable membrane

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