Victory for the ACT Student Text 15e

332 • S CIENCE

EXPLANATIONS

5. The best explanation for biomass being measured as dry weight is: A. if water weight were included, ‡ˆϐ‹…‹‡…› ”ƒ–‹‘• ƒ– ‡ƒ…Š –”‘’Š‹…Ž‡˜‡Ž would be unpredictable. Ǥ „‘†› ϐŽ—‹†•…‘–”‹„—–‡ Ž‹––Ž‡ –‘ –Š‡ mass of marine organisms. C. water molecules contain little or no usable chemical energy. D. each trophic level contains a different amount of water.

5. (C) Science/Evaluation of Models/Analysis Š‡ †‡ϐ‹‹–‹‘ ‘ˆ „‹‘ƒ••ǡ ƒ• ‹†‹…ƒ–‡† in the footnote, states that dry weight ”‡ϐŽ‡…–• –Š‡ —•ƒ„Ž‡ chemical energy stored at each trophic level. Since water weight represents no additional usable energy, it is not included in measures of biomass.

The graph below shows various characteristics of the different layers of the atmosphere and the boundaries between layers. Passage II

The Cambridge Edge Graphs with this much information …ƒ „‡ †‹ˆϐ‹…—Ž– to understand. Breaking the graph down step by step can help you master the graph and answer any accompanying questions. Start by understanding the relationship between the x - and y- axes. Then add in each additional layer of information, keeping in mind how these pieces ϐ‹– ‹ ™‹–Š –Š‡ x - and y- axes.