Suzy's science class is studying changes in particle motion during phase changes. Suzy is asked to add a few pieces of dry ice to a flask and cover it with a balloon. After a few minutes she observed the balloon starting to inflate. How can she explain this? A) The cooling effect of the dry ice as it undergoes a phase change from solid to liquid expands the gas and inflates the balloon. B) While the dry ice cools the flask, it undergoes a phase change from solid to liquid. The greater freedom of the particles expands the balloon. C) As the temperature rises, the dry ice undergoes a phase change from solid to gas. The expanding gas molecules exert pressure on the walls of the balloon. D) The dry ice particles under go a phase change from solid to liquid as it warms to room temperature and experiences an increased volume which inflates the balloon.

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

Epinephrine is a hormone released from the adrenal gland of the body, most often in a stressful situation. it is known as the "fight-or-flight" hormone. one way that it causes a response in the body is to activate receptors on muscle cells. where are these cellular receptors located? a. on the cell membrane b. in the nucleus c. on the cell wall d. around the mitochondria

In a classic experiment using pea shape, mendel conducted two separate genetic crosses. in the first cross the parent plants were “true breeding” for pea shape; one had round peas ( r )and the other had wrinkled (r). the first cross produced a filial 1 generation of all round peas. in the second cross, mendel bred plants from the filial 1 generation. this cross produced different results. out of approximately 1000 plants, about 75% were round and 25% were wrinkled.