B flower in the fall C do not have a critical photoperiod. D, all of these are correct. 12, whihch is NOT a physiological change related to photoperiodism? C, breaking bud dormancy D、 seed germination E、 root bra 13, Which statement is NOT true about photoperiodism? aA day-neutral plant flowers according to some form of regulation other than B, A short-day plant flowers when the day length is shorter than some critical length C, The phytochrome form Pfr is converted to Pr in daylight, producing the active form that induces flowering in long-day plants D, A long-day plant will flower even when the day period is not long enough if there is a short period of light during the dark period 14, Which of the following statements is NoT true about the germinated pollen grain? A, The pollen tube forms between cells of the style b Germination occurs on the surface of the stigma C, There are two sperm nuclei that move down the pollen tube to the micropyle D, The pollen tube nucleus generates the pollen tube E, Fertilization occurs when the pollen grain germinates 15, A plants response to the relative amounts of daylight and darkness is knownas C、 phototropism D、 photoperiodism 16. Flower buds develop from A. shoot apical meristem only B. axillary buds only C. either axillary buds or apical buds D. the same buds as leaves only 六、填空题( Put the best word in the blanks) 1、1920年,美国科学家 发现光周期影响植物的开花。 2、光周期诱导开花的成花素假说是由提出的。 在1939年提出低温刺激诱导植物产生春化素 4、植物体内存在着能处理来自于光的能量和信息的至少有3类光系统。它们是 和 5、植物在春化作用中感受低温影响的部位为 6、花粉的识别物质是 7、雌蕊的识别感受器是柱头表面的 8、要想使菊花提前开花可对菊花进行 处理,要想使菊花延迟开花,可对菊花进 处理。 9、影响花诱导的主要外界条件是 和 10、据成花素假说,成花素是由 两组活性物质组成 七、问答题( Answer the following question) 1、烟熏植物(如黄瓜)为什么能增加雌花? 2、柴拉轩提出的成花素假说的主要内容是什么?A、are the same as long-day plants B、are apt to flower in the fall. C、do not have a critical photoperiod. D、all of these are correct. 12、whihch is NOT a physiological change related to photoperiodism? A、some flowering B、onset of senescence C、breaking bud dormancy D、seed germination E、root branching 13、Which statement is NOT true about photoperiodism? A 、 A day-neutral plant flowers according to some form of regulation other than photoperiodism. B、A short-day plant flowers when the day length is shorter than some critical length. C、The phytochrome form Pfr is converted to Pr in daylight, producing the active form that induces flowering in long-day plants. D、A long-day plant will flower even when the day period is not long enough if there is a short period of light during the dark period. 14、Which of the following statements is NOT true about the germinated pollen grain? A、The pollen tube forms between cells of the style. B、Germination occurs on the surface of the stigma. C、There are two sperm nuclei that move down the pollen tube to the micropyle. D、The pollen tube nucleus generates the pollen tube. E、Fertilization occurs when the pollen grain germinates. 15、A plant’s response to the relative amounts of daylight and darkness is knownas A、bolting B、apical dominance C、pototropism D、photoperiodism 16、Flower buds develop from A．shoot apical meristem only B. axillary buds only C. either axillary buds or apical buds D. the same buds as leaves only 六、填空题(Put the best word in the blanks) 1、1920 年，美国科学家___________和_____________发现光周期影响植物的开花。 2、光周期诱导开花的成花素假说是由_____________提出的。 3、____________在 1939 年提出低温刺激诱导植物产生春化素。 4、植物体内存在着能处理来自于光的能量和信息的至少有３类光系统。它们是 _________________、_________________和__________________。 5、植物在春化作用中感受低温影响的部位为_____________。 6、花粉的识别物质是_____________。 7、雌蕊的识别感受器是柱头表面的_____________。 8、要想使菊花提前开花可对菊花进行__________处理，要想使菊花延迟开花，可对菊花进 行____________处理。 9、影响花诱导的主要外界条件是___________和___________。 10、据成花素假说，成花素是由__________和___________两组活性物质组成。 七、问答题(Answer the following question) 1、烟熏植物（如黄瓜）为什么能增加雌花？ 2、柴拉轩提出的成花素假说的主要内容是什么？