题干

右下图是用不透水的云母片以不同方式分别插入三株燕麦幼苗的胚芽鞘尖端部分,并分 别从不同方向给以光照,培养一段时间后,胚芽鞘的生长情况是 (    )

A:甲向左弯,乙不弯曲,丙向右弯

B:甲不弯曲,乙不弯曲,丙向右弯

C:甲向右弯,乙不弯曲,丙向左弯

D:甲向左弯,乙向右弯,丙不弯曲

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B

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    In a paper published in the journey Science Advance, researchers describe how Matabele ants, a species of large ant known for attacking termite colonies (白蚁群落), will, after the battle, pick up injured fellow soldiers and carry them back to the nest where they can recover.

    The paper is the latest in a growing body of research that this form of helping behavior, previously observed in some mammals and birds, may not require complex emotion, and may, therefore, be far more widespread in nature than previously thought.

    “Here we have an example of an individual saving another individual,” says lead researcher Erik Frank who conducted the research. “We can be quite certain that the ants don't know why they are doing what they are doing.”

    It's a behavior that pays off for the colony. Our classic conception of worker ants is that they are essentially abandoned, but Mr. Frank and his colleagues calculated that the practice of rescuing nest mates results in a colony size that is a 28.7 percent larger than it would be had the ants left their fellow soldiers for dead.

    “These injured ants are able to recover from their injuries, ” says Frank. “They are essential for the safety and the betterment of the colony. ”

    When a Matabele ant is injured, as often happens during battles with termites, its body will give off two smelly chemicals that tell other ants to carry it back to the nest. Indeed, the researchers found that using these chemicals to seek help from uninjured ants will effectively activate the rescue behavior, supporting their theory that the ants were acting on pure instinct(本能), not more complex emotions.

    “The more we study rescue behavior in ants and other animals, the more we are going to realize that it's not just limited to the species we've observed so far, ” says Karen Hollis, a professor at Mount Holyoke College, mentioning studies that found that dolphins help other injured dolphins to the surface for air, capuchin monkeys defend each other during intergroup battles, and rats free other rats that are trapped.