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Organisms and Populations — BIOLOGY STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 ScienceBIOLOGYOrganisms and Populations3 Marks
Question
  1. Explain any two defence mechanisms plants evolved against their predators.
  2. How does predation differ from parasitism?
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Answer

  1.  
  1. Thorns are (morphological) means of defence.
  2. produce/store chemicals which inhibit digestion/disrupts reproduction/kill/Calotropis produces highly poisonous cardiac glycosides/plants may produce chemicals such as nicotine/caffiene/quinine/strychnine/opium are produced as defence.
  1.  
Parasitism Predation
Lives & feed on the host. Only feeds on prey.
host specific. prudent/not prey specific.
Co-evolve with the host. Control/check prey population.

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