题干

研究小组将生长状况相似的菠菜幼苗均分为A、B两组进行实验探究,A组培养在完全培养液中,B组培养在缺Mg2+的培养液中,其他条件相同且适宜.一段时间后,持续提供14C标记的CO2进行光合作用,然后检测并比较14C标记的有机化合物的量.请回答下列问题.

(1)该实验的目的是____ .

(2)B组14C标记的(CH2O)的量比A组低,原因是____ 

(3)在检测过程中,发现6s后有十余种产物含有放射性,而0.5s内只发现一种产物含有放射性,这种产物最可能是____ 

(4)实验中的“其他条件”主要是指____ (至少答两项).若在实验过程中突然停止14CO2供应,则此时两组实验中14C的含量均会____ ,比值会____ .

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答案(点此获取答案解析)

\u63a2\u7a76Mg2+\u5bf9\u690d\u7269\u5149\u5408\u4f5c\u7528\u7684\u5f71\u54cd,\u7f3a\u5c11\u9541\u79bb\u5b50\u4e0d\u5229\u4e8e\u53f6\u7eff\u7d20\u7684\u5408\u6210\uff0c\u5149\u53cd\u5e94\u4ea7\u751f\u7684H\u548cATP\u4e0d\u8db3\uff0c\u4e09

同类题1

阅读下面短文,从短文后所给的A、B、C、D四个选项中选出能填入相应空白处的最佳选项。

    Do you often communicate with your parents?

    Some parents are always comparing their 1 with themselves when they were young, or with other people when they were children.

    “When I was your age,” a father said to 2sixteen-year-old son one day, “I was at the top of my class every year. And I 3 what I wanted to do when I left school. I had goals. You have no goals, 4your are always at the bottom of your class .”

    The man's son said nothing. He had already heard this from his father 5 times.

    “And when your mother was your age,” the young man's father, 6 , “She had a good job and she was earning money. You don't even have a part-time job. You earn nothing.”

    The man's son still said 7. He had heard this before, 8.

    “And 9 your elder brother was your age,” the young man's father went on, “he studied hard. But your just 10your time.”

    And the man's son still said nothing.

    Finally, the young man's 11 said, “And when Abraham Lincoln was your age, he worked all day and studied at night.”

    This time the son 12 stay silent(沉默).

    “And when Abraham Lincoln was your age, father,” he said, “He was the president of13United States. 14 are you?”

    His father had no answer to this.

    Are your parents always comparing you 15 others? And what's your reply? Do you have a better way to communicate with each other?