Question: 102. Auxin is used by gardeners to prepare weed-free lawns. But no damage is caused to grass as auxin
(1) promotes apical dominance.
(2) promotes abscission of mature leaves only.
(3) does not affect mature monocotyledonous plants.
(4) can help in cell division in grasses, to produce growth.
Answer: Option (3)
Explanation:
Synthetic auxins are commonly used as selective herbicides to remove weeds from lawns.
These auxins are effective mainly against dicotyledonous plants and cause abnormal growth leading to their death.
Grasses are monocotyledonous plants and are not significantly affected by these auxins.
Hence, auxin can eliminate weeds without causing damage to grass in lawns.
Therefore, the correct reason is that auxin does not affect mature monocotyledonous plants.