题干

将紫色洋葱鳞片叶表皮细胞浸润在0.3g/mL的蔗糖溶液中,1分钟后进行显微镜观察,结果如图,下列叙述错误的是(    )

A:图中L是细胞壁,M是液泡,N是细胞质

B:将视野中的细胞浸润在清水中,原生质体会逐渐复原

C:实验说明细胞膜与细胞壁在物质透过性上存在显著差异

D:洋葱根尖分生区细胞不宜作为该实验的实验材料

上一题 下一题 0.0难度 选择题 更新时间:2016-04-27 03:05:16

答案(点此获取答案解析)

A

同类题3

完形填空

   Since finishing my studies at Harvard and Oxford, I've watched one friend after another land high-ranking, high-paying Wall Street jobs. As executives (高级管理人员) with banks, consulting firms,established law firms, and major corporations, many are now 1on their wayto impressive careers. By society's2, they seem to have it made.

   On the surface, these people seem to bevery lucky in life. As they left student life behind, many had a3drink attheir cheap but friendly local bar, shook hands with longtime roommates, and4out of small apartments into high buildings. They made reservations atrestaurants where the cost of a bottle of wine5a college year's monthlyrent. They replaced their beloved old cars with expensive new sports cars.

    The thing is, a number of them have6 thatdespite their success, they aren't happy. Some 7of unfriendly coworkers andfeel sad for eight-hour workweeks devoted to tasks they 8. Some do notrespect the companies they work for and talk of feeling tired and 9. However, instead of devoting themselves to their work, they find themselvesworking to support the10 to which they have so quickly become11.

     People often speak of trying a more satisfying path, and 12 in the end the idea of leaving their jobs to workfor something they   13 or finding a position that would give themmore time with their families almost always leads them to the same conclusion: it's14 . They have loans, bills, a mortgage(抵押贷款)to 15, retirement to save for.They recognize there's something 16in their lives, but it's 17to stepoff the track.

    In a society that tends to18 everything in terms of dollars andcents, we learn from a young age to consider the costs of our19infinancial terms. But what about the personal and social costs  20 in pursuing money over meaning? These are exactly the kinds of costsmany of us tend to ignore — and the very ones we need to consider most.