Plant Physiology give the pollen tubes an internal force to reject the will of t
ID: 268311 • Letter: P
Question
Plant Physiology
give the pollen tubes an internal force to reject the will of the non-self RNases l Ergeted to the proteosome for degradation 30) Organisms that undergo dehydration/desiccation at some point in their life cycle, whether it be seeds or "sea monkcys you may order from the back of a comic book, accumulate compatible solutes". Give an example of a compatible solute (remember "Beans, beans, the musical fruit?) and explain the function of compatible solutes (2 points) 25 SEA-MONKEYS Which hormone is directly responsible the precise programmed cell death in the abscission zone of a senescing leaf when it is shed in the autumn? 31) A) Cytokinin B) Abscisicacid) Gibberellins D) Ethylene E) Auxins ) Pollen tubes are some of the fastest growing cells known. In corn for example, the pollen tube can grow twelve inches or more down the style (the com silk) and into the husk to fertilize the egg on A) The pollen tube receives an abundance of nutrients and photoassimilate from the style to sustair ) The pollen tube concentrates it cytoplasm at the growing tip and seals off the older empty tube the inflorescence (the immature corncob) in a few hours. To do this this growth ) Asymmetric cell divisions keep the cytoplasm at the growing tip with numerous highly vacuolated D) The sperm cells secrete RNases ahead of them, creating a tube of dead cells through which they E) The pollen tube differentiates from style tissue to provide a path for the sperm to swim through cells behind swimExplanation / Answer
31. The correct answer is D.
ethylene is present in abundance at the time of programmed cell death.
32. The correct answer is B.
calcium is required for the growth of pollen tube which is present in the cytoplasm. so, cytoplasm conatining calcium concentrated at the tip of pollen tube to grow it fast.