NEW TOEFL Reading Practice Test #1

Explanation:

The passage discusses how birds "can travel thousands of miles between breeding and wintering grounds, often returning to the exact same locations year after year." The phrase "exact same locations" emphasizes accuracy, not speed, distance, or strength. Scientists seek to understand "the mechanisms that enable such precision," referring to the remarkable accuracy with which these animals navigate. The context makes it clear that precision refers to the exactness or accuracy of their navigation, not how fast they travel (speed), how far they go (distance), or how powerful they are (strength). The word "exact" in the previous sentence is a strong contextual clue pointing to accuracy.

Explanation:

The passage explicitly states: "At night, some species navigate by the stars, particularly using the North Star and surrounding constellations as fixed reference points." This directly supports option C. Option A is incorrect because the moon is not mentioned in the passage. Option B is not discussed as a navigation method. Option D is incorrect because the word "solely" makes it too extreme; the passage indicates birds use multiple navigation strategies, not just one. Additionally, while the passage does discuss magnetic field navigation, the specific question asks about nighttime navigation, and the passage specifically identifies stars for this purpose.

Explanation:

The passage states: "In birds, this sense appears to be located in the eye, where specialized proteins called cryptochromes may allow them to literally see magnetic field lines as patterns of light and dark." This clearly indicates that cryptochromes help birds detect magnetic fields. Option A is too broad; the passage only discusses cryptochromes in birds, not all animals. Option C involves a comparison not made in the passage; there's no ranking of importance between different navigation methods. Option D might be tempting, but the passage doesn't provide any information about when cryptochromes were discovered. The inference must be based on what the passage actually states, which is the function of cryptochromes in magnetic field detection.

Explanation:

After discussing magnetoreception in birds, the passage states: "Sea turtles, salmon, and even some bacteria use magnetic sensing to navigate." The word "even" before bacteria suggests the author is showing the breadth of this ability across very different types of organisms. The purpose is to demonstrate that magnetoreception is not unique to birds but exists across diverse species, from complex vertebrates like turtles and fish to simple bacteria. Option B is incorrect because there's no comparison of advancement. Option C is wrong because all these animals are described as using the same method (magnetoreception), not different methods. Option D suggests an evolutionary claim that the passage does not make; the passage simply notes that these diverse organisms share this ability.

Explanation:

The passage explains: "animals seem to detect both the direction and the intensity of magnetic fields, allowing them to determine not just which way is north, but also their approximate latitude and longitude, much like a natural GPS system." This clearly indicates that by detecting both direction and intensity, animals can determine their geographic position (latitude and longitude), not just direction. Option A is not mentioned; weather prediction is not discussed. Option B is incorrect; the passage discusses navigation, not communication. Option D makes a comparison about speed that the passage does not support; the passage discusses the complementary nature of different navigation systems, not which is faster.