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MODEL PAPER 8 — BIOLOGY STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 ScienceBIOLOGYMODEL PAPER 81 Mark
MCQ
Assertion (A): Tracheae, primary, secondary and tertiary bronchi are supported by incomplete cartilaginous rings.
Reason (R): These rings of cartilage make the wall non-collapsible.
  • A
    Both A and R are true and R is the correct explanation of A.
  • B
    Both A and R are true but R is not the correct explanation of A.
  • C
    A is true but R is false.
  • D
    A is false but R is true.
✓

Answer

(a) Both A and R are true and R is the correct explanation of A.
Explanation: The cartilage rings are present in the trachea to prevent it from collapsing. This enables the lumen of trachea to stay open during breathing.

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