1 El Nino is a short-term climatic change that causes ocean waters to remain warm when they should normally be cool. The warmer temperatures disrupt food webs and alter weather patterns. Which occurrence would most likely result from these changes?

(1) Some species would become extinct, and other species would evolve to take their place.
(2) Some populations in affected areas would be reduced, while other populations would increase temporarily
(3) The flow of energy through the ecosystem would remain unchanged.
(4) The genes of individual organisms would mutate to adapt to the new environmental conditions.

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2 A food pyramid representing relationships in a pond community is shown below.


The energy of the Sun is made available to the pond community through the activities of the organisms at level

(1) A         (3) C
(2) B         (4) D

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3 Eating a sweet potato provides energy for human metabolic processes. The original source of this energy is the energy

(1) in protein molecules stored within the potato
(2) from starch molecules absorbed by the potato plant
(3) made available by photosynthesis
(4) in vitamins and minerals found in the soil

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4 Compared to a natural forest, the wheat field of a farmer lacks

(1) heterotrophs
(2) significant biodiversity
(3) autotrophs
(4) stored energy

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5  Which factor is not considered by ecologists when they evaluate the impact of human activities on an ecosystem?

(1) amount of energy released from the Sun
(2) quality of the atmosphere
(3) degree of biodiversity
(4) location of power plants

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