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Which listing correctly indicates a sequence of increasingly complex biological organization?  

This chart shows the PCB concentrations found at the various trophic levels in the Saginaw Bay ecosystem of Lake Huron. Notice that the fish in the higher trophic levels accumulate more PCBs than those in lower trophic levels. (credit: Patricia Van Hoof, NOAA) Other examples are:  DDT (pesticide) accumulating in birds of prey (raptors), Mercury levels being too high in mackerel, etc. What does the figure below demonstrate?   

If the atomic number of Carbon is 6 and the atomic mass is 12, how many electrons are surrounding the atomic nucleus?  

Which of the following is true about HIV?

Gene pharming is the use of:

Reptiles:

Gene pharming is the use of:

Which of the following is required for natural selection to occur in a population?  

According to experts on Native American religions, how might it harm the Diné to put reclaimed snow on the San Francisco Peaks?

Joseph is a Jew living in the first century CE. He has no interest in Jerusalem and prefers to live in a monastic community, awaiting the coming apocalypse. To which group does Joseph MOST likely belong?