4.等渗溶液是指() A、压力势相等但溶质成分可不同的溶液 B、溶质势相等但溶质成分可不同的溶液 C、溶质势相等且溶质成分一定要相同的溶液 15.蒸腾系数指 A、一定时间内,在单位叶面积上所蒸腾的水量 B、植物每消耗1kg水时所形成的干物质的克数 C、植物制造lg干物质所消耗水分的千克数 16.植物体内的水分向上运输,是因为() A、大气压力 B、内聚力张力 C、蒸腾拉力和根压 17.水在绿色植物中是各组分中占比例最大的,对于生长旺盛的植物组织 和细胞其水分含量大约占鲜重的() A、50%~70% B、90%以上 C、70%90% 18.木质部中水分运输速度比薄壁细胞中水分运输速度() A、快 B、慢 C、一样 9.在下列三种情况中,哪一种情况下细胞吸水() A、外界溶液水势为-0.6MPa,细胞水势-0.7MPa B、外界溶液水势为-0.7MPa,细胞水势-0.6MPa C、两者水势均为-0.9MPa 20.植物的水分临界期是指 A、对水分缺乏最敏感的时期 B、对水需求最多的时期 C、对水利用率最高的时期 21.下列哪一个是目前作为灌溉的生理指标最受重视() A、叶片的含水量 B、叶片气孔开度 C、叶片水势 22.当细胞吸水处于饱和状态时,细胞内的ψ为(MP B、很低 3. Stomates are usually open A. at night, when the plant requires a supply of oxygen B. during the day, when the plant requires a supply of carbon'dioxide C. whenever there is excess water in the soil D. All of these are corr
6 14．等渗溶液是指( ) A、压力势相等但溶质成分可不同的溶液 B、溶质势相等但溶质成分可不同的溶液 C、溶质势相等且溶质成分一定要相同的溶液 15．蒸腾系数指( ) A、一定时间内，在单位叶面积上所蒸腾的水量 B、植物每消耗 1kg 水时所形成的干物质的克数 C、植物制造 1g 干物质所消耗水分的千克数 16．植物体内的水分向上运输，是因为( ) A、大气压力 B、内聚力-张力 C、蒸腾拉力和根压 17．水在绿色植物中是各组分中占比例最大的，对于生长旺盛的植物组织 和细胞其水分含量大约占鲜重的( ) A、50%~70% B、90%以上 C、70%~90% 18．木质部中水分运输速度比薄壁细胞中水分运输速度( ) A、快 B、慢 C、一样 19．在下列三种情况中，哪一种情况下细胞吸水( ) A、外界溶液水势为-0.6MPa，细胞水势-0.7MPa B、外界溶液水势为-0.7MPa，细胞水势-0.6MPa C、两者水势均为-0.9MPa 20．植物的水分临界期是指( ) A、对水分缺乏最敏感的时期 B、对水需求最多的时期 C、对水利用率最高的时期 21．下列哪一个是目前作为灌溉的生理指标最受重视( ) A、叶片的含水量 B、叶片气孔开度 C、叶片水势 22．当细胞吸水处于饱和状态时，细胞内的ψw 为( )MPa A、0 B、很低 C、 >0 23．Stomates are usually open A．at night, when the plant requires a supply of oxygen. B．during the day, when the plant requires a supply of carbon’dioxide. C．whenever there is excess water in the soil. D．All of these are correct
4. When a cell is placed in higher water potential solution B. water exits the cell toward the solution 25. Water flows from the A. higher water potentiae to the lower water potential ntial to the higher wate C. Lowerψ to the higherψ 26. Root hairs do not play a role in B C water uptake parian strip A. how water and minerals move into the wascular cylinder B how water but not minerals move C. how minerals but not water moves D. neither the flow of water nor the flow of minerals into a plant 28. which force is the central causative agent of the transpiration- cohesion- tensin theory of xylem transport? A transpiration pull C. root D. atmospheric pressure 29. which term describes forcing water out of the plant at the edges of its leaves A. root pressure B. gutta D. transpiration pull 30. which force pushes water into the xylem as osmosis moves water into the
7 24．When a cell is placed in higher water potential solution. A．water enters the cell. B．water exits the cell toward the solution. C．water enters and solute exits the cell. 25．Water flows from the A．higher water potentiae to the lower water potential. B．lower water potential to the higher water potential C．Lower ψπ to the higherψπ 26．Root hairs do not play a role in A. oxygen uptake B. mineral uptake C. water uptake D. carbon dioxide uptake 27. The Casparian strip affects A．how water and minerals move into the wascular cylinder. B. how water but not minerals move C. how minerals but not water moves D. neither the flow of water nor the flow of minerals into a plant. 28. which force is the central causative agent of the transpiration- cohesiontensino theory of xylem transport ? A. transpiration pull B. guttation C. root pressure D. atmospheric pressure. 29. which term describes forcing water out of the plant at the edges of its leaves? A．root pressure B. guttation C. atmospheric pressure D. transpiration pull 30. which force pushes water into the xylem as osmosis moves water into the root?