How do scientists estimate the atmospheric levels of carbon dioxide that existed on Earth hundreds or thousands of years ago?
A) They deduce it from the carbon dioxide content of fossil fuels.
B) They measure it from bubbles of gas trapped in Antarctic ice.
C) They estimate it from the relative numbers of carbon-based life forms that existed over time.
D) They measure it from erupting volcanoes, bubbling hot springs, and seeping hydrothermal vents.
B
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Indicate whether the statement is true or false.
Which plant cell structure is comprised of approximately 300 chlorophyll molecules and about 40 carotenoid
pigments, organized together to optimize the capture of light energy?
a. reaction center b. chlorophyll c. antenna complex d. cytochrome complex e. stomata
What is extinction an example of?
a. mendelian genetics b. natural selection c. macroevolutionary change d. microevolutionary change
An inverted energy pyramid for an ecosystem, one where there are more consumers than producers at a given point in time, is possible if which of the following is true?
Select one: a. Producers are reproducing more slowly than consumers. b. There is intense sunlight for long periods of time, as in the tropics. c. Producers are reproducing much more rapidly than consumers. d. Decomposers are reproducing much more rapidly than consumers. e. Consumers are reproducing more rapidly than producers.