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Plant Growth and Development — BIOLOGY STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 ScienceBIOLOGYPlant Growth and Development2 Marks
Question
  1. Which phytohormone is also called a stress hormone? How does this hormone overcome stress conditions?
  2. Name the phytohormone, which is widely used to kill the dicotyledonous weeds?
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Answer

  1. Abscisic acid is the stress hormone.
  • It causes closure of stomata and increases the tolerance of plant to water stress.
  • It induces dormancy in seeds and thereby helps the plant to withstand dessication and other unfavourable factors that affect plant growth.
  1. 2, 4 dichlorophenoxy aceitic acid.

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