题干

下列是有关光合作用和呼吸作用的实验装置,认真分析下列说法,找出错误的选项(    )

①在进行图一实验之前要先将植物暗处理,目的是将叶片中原有的淀粉运走耗尽

②图一中甲叶片的遮光部分和见光部分形成一组对照实验,可验证光照是光合作用的条件

③图一中的丙叶片与甲叶片形成一组对照实验,可验证光合作用的产物是淀粉

④图一中的乙叶片与丁叶片形成一组对照实验,变量是水分

⑤图一中的叶片酒精脱色后滴加碘液,变蓝的有甲叶片的见光部分、乙叶片、丙叶片的绿色部分

⑥图二可以验证种子的萌发时呼吸作用释放出了二氧化碳

⑦图二在倒水之前将一点燃的蜡烛放进瓶内会立刻熄灭,说明种子的呼吸作用放出了二氧化碳

⑧若将图二中萌发的种子换成一盆绿色植物,放在光照下实验现象会更明显

A:①③④⑤⑦⑧

B:③⑤⑦⑧

C:③④⑤⑦⑧

D:①④⑤⑥⑦⑧

上一题 下一题 0.0难度 选择题 更新时间:2019-04-07 11:53:27

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C

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    People with an impulsive personality refer to those who tend to do things without considering the possible dangers or problems first. According to a new study by researchers at the University of Georgia, such people may be more likely to have food addiction. The study found that people exhibiting impulsive behavior weren't necessarily overweight, but impulsiveness was related to a direct relationship with food, and therefore, less healthy weight.

    Food addiction has been compared to addictive drug use. Studies have linked the dopamine (多巴胺) release that occurs after tasting delicious food to the dopamine release that happens when people consume other addictive substances.

    Impulsive behavior involves several personality traits (特点). Two of these traits, known as negative urgency and lack of perseverance, were particularly associated with food addiction and high BMI (身体质量指数) during the study.

    Negative urgency is characterized by the tendency to behave impulsively when experiencing negative emotions. Some people might drink alcohol or take drugs. For others, it could mean eating to feel better. Lack of perseverance is when a person has a hard time finishing hard or boring tasks. People with a lack of perseverance might have difficulty attempting to change addictive eating behavior, which could also cause obesity.

    “Impulsiveness might be one reason why some people eat in an addictive way despite motivation to lose weight,” said Dr. Ashley Gearhardt, a clinical psychologist. He was involved in developing the Yale Food Addiction Scale in aid of those people. “We are theorizing that if food addiction is really a thing, then our measure, the Yale Food Addiction Scale, should be related to helping control impulsive action,” said Gearhardt.

    Clinical psychologist Dr. James MacKillop, whose lab was conducting the study, believes that therapies used to treat addictive drug behavior could help people who suffer from addictive eating habits.

    “Most of the programs for weight loss at this point focus on the most obvious things, which are clearly diet and exercise,” MacKillop said. “It seems that managing strong desires to eat would naturally fit in with the skills a person would need to eat healthily.”