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NEETBotanyPlant - Growth and Development

A particular plant growth regulator is chemically an indole compound. From which of the following sources was this growth regulator first isolated?

Options

  1. AAutoclaved herring sperm DNA
  2. BHuman urine
  3. CFungus Gibberella fujikuroi
  4. DRipened oranges

Correct answer

B. Human urine

Step-by-step solution

Plant growth regulators that are indole compounds refer to auxins (e.g., indole-3-acetic acid or IAA). According to NCERT, auxin was first isolated from human urine. Autoclaved herring sperm DNA is the source from which cytokinin (kinetin) was discovered. The fungus Gibberella fujikuroi is associated with the discovery of gibberellins (gibberellic acid). Ripened oranges are associated with the discovery of the gaseous hormone ethylene. Answer: Human urine

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