5 What is the term for growth in response to gravity? B phot C growth regulator D gravitropism 6 What is girdling and how does it kill a tree? A. Girdling is the process by which all the leaves are stripped away preventing the tree from photosynthesizing B. Girdling strips away the secondary phloem, disrupting the flow of water to the leaves C. Girding strips away the secondary xylem, disrupting the flow of photosynthates to the roots D. Girdling strips away the secondary phloem, disrupting the flow of photosynthates to the oots. Ca. Girdling is associated with the stem system 7 How would phototropism be beneficial to plants? A. By keeping the leaves oriented perpendicularly to light, the plant can increase water loss B. By keeping the leaves oriented parallel to light, the plant can increase water loss C. By keeping the leaves oriented perpendicularly to light, the plant can increase the D. By keeping the leaves oriented parallel to light, the plant can decrease the photosynthesis 8 Which of the following wavelengths of light would stimulate germination? A 450 nm B 540 nm C 660 nm D. 730 nm 9根中最大的伸长区具有下列哪一个特征 A.DNA的复制B.细胞分裂C.液泡的形成D.细胞的分化 10促进莴苣种子萌发的光是 A.蓝紫光 B.远红光 C.红光 红光后再一个远红光 11长波光有利于植物细胞的 A.伸长生长 B.横向生长 C.壁的加厚 D.细胞分化 12植物正常生长需要 A.昼夜温度都高 B.较高日温较低夜温 C.较低日温较高夜温 D.昼夜都是25℃ 13植物离体部分具有恢复植株其余部分的能力叫作 A.极性 B.再生作用 C.生长相关性 D.细胞分化 14种子萌发需要光的植物有 A.烟草 B.莴苣 C.番茄 15土壤中氮素供应不足,会使植物根冠比 A.增加 B.降低 C.不变 16黄化幼苗被照射下列哪种光时,不利于其形态建成 A.红光 B.远红光 C.绿光5 What is the term for growth in response to gravity? A. tropism B. phototropism C. growth regulator D. gravitropism 6 What is girdling and how does it kill a tree? A. Girdling is the process by which all the leaves are stripped away preventing the tree from photosynthesizing. B. Girdling strips away the secondary phloem, disrupting the flow of water to the leaves. C. Girding strips away the secondary xylem, disrupting the flow of photosynthates to the roots. D. Girdling strips away the secondary phloen, disrupting the flow of photosynthates to the roots.Ca. Girdling is associated with the stem system. 7 How would phototropism be beneficial to plants? A. By keeping the leaves oriented perpendicularly to light, the plant can increase water loss. B. By keeping the leaves oriented parallel to light, the plant can increase water loss. C. By keeping the leaves oriented perpendicularly to light, the plant can increase the photosynthesis rate. D. By keeping the leaves oriented parallel to light, the plant can decrease the photosynthesis rate. 8 Which of the following wavelengths of light would stimulate germination? A. 450 nm B. 540 nm C. 660 nm D. 730 nm 9 根中最大的伸长区具有下列哪一个特征 A. DNA 的复制 B. 细胞分裂 C. 液泡的形成 D. 细胞的分化 10 促进莴苣种子萌发的光是________ A. 蓝紫光 B. 远红光 C. 红光 D. 红光后再一个远红光 11 长波光有利于植物细胞的________ A. 伸长生长 B. 横向生长 C. 壁的加厚 D. 细胞分化 12 植物正常生长需要________ A. 昼夜温度都高 B. 较高日温较低夜温 C. 较低日温较高夜温 D. 昼夜都是 25℃ 13 植物离体部分具有恢复植株其余部分的能力叫作________ A. 极性 B. 再生作用 C. 生长相关性 D. 细胞分化 14 种子萌发需要光的植物有________ A. 烟草 B. 莴苣 C. 番茄 15 土壤中氮素供应不足，会使植物根冠比________ A. 增加 B. 降低 C. 不变 16 黄化幼苗被照射下列哪种光时，不利于其形态建成 A. 红光 B. 远红光 C. 绿光