Compare the productivities of a swamp and a river, and give two reasons for the difference

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

Which of the following does not describe a physical property of iron? a iron is silvery-white or gray in color. b iron has a boiling point of about 3,000°c. c iron is a magnetic element . d iron and sulfur react to form iron sulfide.

Listed in the item bank are some key terms and expressions associated with the categories seen in the venn diagram. to find out more information about items, some have more details available when you click on them. drag and drop each item onto the proper area of the diagram. if an item describes more than one category, be sure to place it in the overlapping space. viruses are tiny infectious pathogens that cause many different diseases, such as polio, and the flu. though they are similar to one celled organisms in some ways, in many ways they are very different. use the venn diagram below to show the similarities and differences between viruses and living organisms.