Which of these is a difference between DNA and RNA? DNA is found in the nucleus; RNA is never found in the nucleus.
DNA consists of five different nucleotides; RNA consists of four different nucleotides.
RNA is double-stranded; DNA is single-stranded.
DNA contains thymine; RNA contains uracil.
In DNA, adenine pairs with guanine; in RNA, adenine pairs with thymine.

Read the following scenario to answer the following question. 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. when most populations of a wide-ranging amphibian species are lost and the few remaining populations are widely separated, we expect to see that a. the founder effect becomes increasingly important b. microevolution no longer occurs c. gene flow between populations is reduced d. artificial selection becomes a greater factor in microevolution

Of seawater increases with decrease in the temperature. therefore, the cold water sinks to the deeper layers at the bottom

Which mechanism of transport takes place when solute particles move from a region of high concentration to a region of low concentration? active diffusion isotonic osmosis