l need help with question 28 and 32 8) Sporophytic self-incompatibility involves
ID: 269937 • Letter: L
Question
l need help with question 28 and 32
8) Sporophytic self-incompatibility involves genetic provides the potter and the sti ives genetic "communication" between the sporophyte tha gma of the sporophyte that harbors the egg cells. This signaling is possible because the pollen is A) Gametophyte tissue only B) Gametophyte cells with maternal material in the pollen coat Two gametophyte sperm cells and a matermal pollen tube cell D) Gametophyte cells and triploid endosperm E) Gametophyte cells incased inside sporophyte cells 29) During gametophytic self-incompatibility. RNases from the receiving tibility RNases from the receiving style enter the growing poller A in the pollen tube IF the RNase is recognized as "self" this kills the len tube. If the RNase is recognized as 'non-self phosphor-transfer proteins phosphorylate the non-self RNases to inactivate them awd e continued pollen tube growh 5) Cells in front of the pollen tube commit suicide in a hypersensitive response to make space D) Non-self RNases are tagged with ubiquitin and targeted to the proteosome for degradation. 6) Midi-chlorians give the pollen tubes an intermal force to reject the will of the non-self RNases in a process called "pollen tube canalization" 30) Organisms that undergo dehydration/des SEA-MONKEYS point in their life cycle, whetdher ir te seds or sea monkeys" 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"7) and explain the function of compatible solutes (2 points) stablipe pvotoin amino aod -prolive 31) Which hormone is directly responsible the precise programmed cell death in the abscission zone of a A) Cytokinin B) Abscisic acid C) Gibberellins D) Ethylene E) Auxins 32) 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 corn 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 sustain B) 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 C) Asymmetric cell divisions keep the cytoplasm at the growing tip with numerous highly vacuolated cells behind 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 swimExplanation / Answer
28)
Correct option:
Explanation: Sporophyte is a diploid multicellular stage in the life cycle of a plant. It is developed from zygote after getting fertilized with haploid egg and sperm cells. Sporophyte contains double sets of chromosomes. Sporophyte self - incompatibility is prevented by recognizing the self-cells and prevent interbreeding. Hence option C is correct
32)
Correct option:
Explanation: The growth of pollen tube is due to chemotropism. The pollen tube starts sensing the chemicals released by egg cells and grows down through the style. It differentiates itself from the surrounding cells of style to deliver the sperm cell through micropyle of the egg cell. Hence, option E is correct.
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