题干

图1表示是将A、B两种植物的叶片分别放置在相同的密闭小室中,给予一定的光照,利用红外测量仪每隔5min测定小室中的CO2浓度.图2表示给予不同强度的光照,测定A、B两种植物叶片的CO2吸收量和CO2释放量(注:实验中所用的A、B两种植物叶片叶面积相等,且实验都在相同且适宜的温度下进行,忽略光照对呼吸作用的影响)

请据图分析回答:

(1)由图1分析可知,A、B植物叶片的光合作用强度受____ 的影响.从实验开始到10min这段时间内,A植物叶片干重的变化趋势是____

(2)若A植物在第5min时,光照突然降低而其他条件不变,三碳化合物合成速率将____ .

(3)在第25﹣40min期间,两个密闭小室内CO2含量相对稳定的原因是____ .从实验开始到第40min这一阶段,A植物积累的有机物量比B植物要____ 

(4)根据2,当光照强度为c klx时,A植物叶片中叶绿体吸收CO2的速率是____ mg/m2•h,一昼夜中B植物增加的葡萄糖为____  mg/m2(设每日光照12小时,保留二位小数).

上一题 下一题 0.0难度 选择题 更新时间:2018-02-18 05:02:32

答案(点此获取答案解析)

CO2浓度,增加,减少,光合作用吸收的CO2 和呼吸作用释放的CO2 速率相等,少,7,49.09

同类题2

    Sunday is more like Monday than it used to be. Places of business that used to keep daytime “business hours” are now open late into the night. And on the Internet, the hour of the day and the day of the week have become irrelevant. A half century ago in the United states, most people experienced strong and precise dividing lines between days of rest and days of work, school time and summer time. Today the dividing lines are still there, but they seem not clear.
    The law in almost all states used to require stores to close on Sunday; in most, it no longer does. It used to keep the schools open in all seasons except summer, in most, it still does. And whether the work week should strengthen its legal(法律的)limits, or whether it should become more changeable, is often debated(争论). How should we, as a society, organize our time? Should we go even further in relaxing the dividing lines of time until we live in a world in which every minute is much like every other?
    These are not easy questions even to ask. Part of the difficulty is that we seldom recognize the “law of time” even when we meet it face to face. We know as children that we have to go to  school a certain number of hours, a certain number of days, a certain number of years – but unless we meet the truant officer(学监), we may well think that we should go to school because of social custom and parents’ requirement rather than to the law. As adults we know “extra pay for overtime working” very well, but less familiar with the fact that what constitutes(构成)“overtime” is a matter of legal thing. When we turn the clock forward to start daylight – saving time, have we ever thought to ourselves: “Here is the law in action”? As we shall see, there is a lot of law that has great influence on how organize and use time: compulsory education law, overtime law, and daylight-saving law – as well as law about Sunday closing, holidays, being late to work, time zones, and so on. Once we begin to look for it, we will have no trouble finding a law of time to examine and assess.