The amount of carbon on this Earth does not change. However, where the carbon is located does change. These locations are referred to as sources and sinks. Sources are areas that add carbon to the atmosphere and sinks are areas that remove carbon from the atmosphere. The sources and the sinks are important to the regulation of green house gasses. Carbon dioxide is one of several green house gasses that keep our planet warm. Too few greenhouse gases in the atmosphere would allow our planet to freeze, too many cause our planet to warm up too much. In the space below describe how humans are disrupting the natural cycle and contributing to the green house gasses in the atmosphere.

Arrange these elements of the intrinsic conduction system in the order that a depolarizing impulse travels during a normal heartbeat. rank from first to last. do not overlap any tiles. view available hint(s) reset av nodeav bundleinternodal pathwaysbundle branchessa nodepurkinje fibers

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

Gregor mendel is best known for his work with pea plants and for uncover many of the mysteries of genetics. one of his major findings stated that there were specific, physical units of inheritance that are transmitted during reproduction. what is the the name given to these units of inheritance which can be found on chromosomes? a) centromeres b) cytoplasm c) genes d) nucleotides