The Venus fly trap closes when

  1. one hair is touched once
  2. it rains
  3. two trigger hairs are touched within a short time
  4. light falls on it
Answer

C) two trigger hairs are touched within a short time

Two stimuli prevent false triggers. AS & A Level Biology · Topic 15 Control and Coordination · 15.2 Control and coordination in plants

Biology MCQ · More A Level Biology: Control and coordination MCQs · Practise