What BEST describes the roles of photosystem I and photosystem II in the process of photosynthesis? A. They form ATP as hydrogen ions cross the thylakoid membrane. B. They absorb sunlight and distribute the energy as heat. C. They transfer electrons from a series of intermediates to form NADPH. D. They absorb sunlight and transfer the energy to electrons.

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

The first signs of cellular differentiation occur in the blastocyst. why is cellular differentiation important for the development of a fully formed human infant?

The response is the basis for vaccination. primary secondary tertiary none of the above