Read the following statements regarding a plant growth regulator that is widely used by gardeners to prepare weed-free lawns: (A) It does not affect mature monocotyledonous plants. (B) It promotes apical dominance. (C) It promotes the abscission of young leaves and fruits. (D) It induces parthenocarpy in tomatoes. How many of the above statements are correct?

Step-by-step solution

The plant growth regulator widely used to prepare weed-free lawns is auxin (specifically 2,4-D). Statement (A) is correct. Auxins like 2,4-D selectively kill dicotyledonous weeds and do not affect mature monocotyledonous plants. Statement (B) is correct. In most higher plants, the growing apical bud inhibits the growth of the lateral buds, a phenomenon called apical dominance, which is mediated by auxins. Statement (C) is incorrect. Auxins help to prevent fruit and leaf drop at early stages (young leaves and fruits