ACT Natural Science: from "Consider the Eel"

31. One of the main ideas established by the passage is

that:

• A. researchers have nearly exhausted their resources

  after spending decades investigating the Sargasso

  Sea.

• B. significant gaps still remain in researchers’ under-

  standing of the life cycle of eels.

• C. eels live their entire lives in the Sargasso Sea, but

  no one has ever seen them there.

• D. female eels turn into silver eels toward the end of

  their lives.

32. Learning about which of the following had the largest

impact on scientists’ current understanding of where

eels breed?

• F. The direction in which ocean currents carry eel

  larvae

• G. The relationship of the yellow eel stage to the

  silver eel stage

• H. Schmidt’s discovery of eel larvae in the Sargasso

  Sea

• J. The adult eels found in the stomachs of other fish

33. The main purpose of the fourth paragraph (lines

34–47) is to describe the:

• A. eels’ transition from freshwater to the ocean.

• B. method of determining the age of eels.

• C. complexity of the Mississippi River system.

• D. river stage of the eel life cycle.

34. The passage states that the Sargasso Sea is set off from

the rest of the Atlantic Ocean by:

• F. the Azores.

• G. several Caribbean countries.

• H. powerful winds.

• J. strong currents.

35. The passage notes that the Sargasso Sea includes:

• A. the eastern North American shore.

• B. the Bermuda Triangle.

• C. certain coastal estuaries.

• D. the mouth of the Mississippi River.

36. As it is used in line 13, the word popular most nearly

means:

• F. well liked.

• G. commonly known.

• H. scientifically accepted.

• J. most admired.

37. As it is used in line 45, the word read most nearly

means to:

• A. learn from print.

• B. observe.

• C. think about.

• D. predict.

38. The passage indicates that female eels’ pupils expand

and turn blue because the eels:

• F. must adapt to see in an environment with much

  less light than they are used to.

• G. are about to undergo a change in their blood

  chemistry.

• H. no longer need to be able to recognize food

  sources since they have stopped eating.

• J. need to be able to recognize the male eels that will

  fertilize their eggs.

39. The passage most strongly emphasizes that the process

of osmosis is necessary for the eels’ transition from:

• A. shallower to deeper water.

• B. feeding to nonfeeding.

• C. immature to mature form.

• D. elver to yellow eel.

40. According to the passage, which of the following characteristics of the eel larvae found by Schmidt provided the best evidence that the larvae were hatched in the Sargasso Sea?

• F. Size

• G. Shape

• H. Color

• J. Species