Demographers developed a hypothesis to explain the changes to the populations of countries over time. This hypothesis describes a demographic transition, in which countries change from a combination of high birthrates and high death rates to low birthrates and low death rates. The changes of
the demographic transition are summarized in the graph.

Sort the statements according to the stage of the demographic transition that they describe

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 picture shows a fishing technique called trawling. how might trawling affect marine biodiversity

Describe the relationship between isotonic solutions, equilibrium, and water movement into and out of a cell.