Heart valves function to heart valves function to control the amount of blood pumped by the heart keep blood moving forward through the heart mix blood thoroughly as it passes through the heart slow blood down as it passes through the heart

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

Blood stem cells may develop into any kind of human blood cells. what kind of stem cells are blood stem cells? a. multipotent stem cells o b. totipotent stem cells o c. pluripotent stem cells o d. unipotent stem cells

Suppose that on a small island off the coast of scotland, 32 percent of the population has blue eyes, which means that these individuals must be homozygous for the blue eye color gene (bb). the only other eye color found on the island is brown, and individuals that are homozygous for the brown eye color gene (bb) or heterozygous (bb) will have brown eyes because brown is the dominant gene. assume this population is in hardy-weinberg equilibrium. if 100 babies are born next year, how many of these would you expect to have brown eyes and be heterozygous? a. 58 b. 49 c. 29 d. 43