Question

claims and arguments
oyster mushrooms, fungi that feed on dead and decaying organisms, have a secret life that belies their innocent appearance. because their diets tend to lack nitrogen, a necessary nutrient for their growth and reproduction, oyster mushrooms have evolved the ability to transform from harmless decomposers into fierce predators when faced with malnourishment.
but how does a seemingly innocuous mushroom kill its prey? lollipop - shaped growths called toxocysts, which contain a molecule known as 3 - octanone. though harmless to most organisms, 3 - octanone is deadly to nematode worms, flooding their nerve cells with calcium and causing system failure. when nematodes push their heads against the toxocysts, the poisonous 3 - octanone is released, paralyzing the hapless creatures within seconds. the oyster mushroom then uses specialized cells called hyphae to engulf the paralyzed nematode.
finally, the hyphae secrete substances that break down the nematode’s body, allowing the mushroom to absorb the nutrients it contains. in this way, the oyster mushroom is able to supplement its diet with the nitrogen it so desperately needs.
what claim does the author make about the oyster mushrooms?
choose 1 answer:

• because oyster mushrooms’ diets typically lack nitrogen, they have developed the ability to hunt prey that provides them with this nutrient.
• because oyster mushrooms are carnivorous by nature, they have adapted to decreasing numbers of prey by also becoming decomposers.
• because oyster mushrooms primarily consume nitrogen, they have evolved to hunt creatures with high nitrogen content.
• because oyster mushrooms’ diets are excessively rich in nitrogen, they have adapted to hunt prey that provides other nutrients they require.

Explanation:

1. Analyze the first option: The passage says oyster mushrooms' diet (feeding on dead/decaying organisms) lacks nitrogen, so they evolved to hunt (transform into predators) when malnourished (lacking nitrogen). This matches the first option's claim.
2. Analyze the second option: The passage states they are decomposers that become predators, not carnivorous by nature and becoming decomposers. So this is incorrect.
3. Analyze the third option: The passage says their diet lacks nitrogen, not that they primarily consume nitrogen. So this is incorrect.
4. Analyze the fourth option: The passage says their diet lacks nitrogen, not is rich in nitrogen. So this is incorrect.

Answer:

A. Because oyster mushrooms' diets typically lack nitrogen, they have developed the ability to hunt prey that provides them with this nutrient.