SAT OwlQuestion bank / Text Structure and Purpose
Hagfish are eel-shaped fish that live on the deep seafloor. When a predator such as a shark bites one, the hagfish releases mucus from glands along its body. In less than a second, the mucus mixes with seawater and swells into a large mass of slime that can clog the attacker's gills. The predator usually lets go, and the hagfish swims away unharmed.
Which choice best states the main purpose of the text?
To explain why hagfish live on the deep seafloor rather than in shallower water
To describe how hagfish defend themselves against predators
To compare the hagfish's defense with the defenses of other deep-sea fish
To argue that hagfish slime could be useful to humans
Show answer and explanation
Answer: B
The text walks through what happens when a predator bites a hagfish: the hagfish releases mucus, the mucus swells into slime that clogs the attacker's gills, and the attacker lets go. The whole text describes this defense, so choice B is correct.
Choice A picks up the detail that hagfish live on the deep seafloor, but the text never explains why they live there.
Why the other choices are wrong
- A. The text mentions the deep seafloor only as a setting detail. It never provides a reason or explanation for why hagfish prefer that habitat over shallower water.
- C. The passage focuses exclusively on the hagfish and its specific mucus defense. It does not mention any other species or compare their defensive strategies.
- D. The text describes the biological function of the slime in escaping predators. It does not discuss potential applications or benefits of hagfish slime for human use.
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