Chromosomes are A: DNA strands that become visible during cell division
B: the control centers of cells
C: the thick, fluid material surrounding the nucleus
D: the basic units of structure in living things

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. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

10111213141516lactic acid fermentation differs from ethyl alcohol fermentation in thato in ethyl alcohol fermentation co2 is also producedlactic acid fermentation can occur in all living thingsethyl alcohol fermentation can only occur in plantsonly lactic acid fermentation can produce more atp

Development has provided electrically for less money but what may be considered a cause of nuclear power