Which of the following statement is correct regarding the plant hormones?
I. They help to coordinate growth, development and responses to the environment.
II. They are synthesised at places away from where they act and simply diffuse to the area of action
Show answer & explanation
Correct answer: C
Explanation
Phytohormones:
Plant hormones are organic chemicals produced by plants that regulate their growth and responses, even in very low concentrations.
Explanation of Statement I: Plant hormones coordinate cell division, stem growth, fruit ripening, and a plant's response to environmental cues (such as light or gravity). For example, auxin helps plants turn toward light.
Explanation of Statement II: Plants do not have a specialized circulatory system like animals. Therefore, hormones are often produced in one location and reach their target area by simple diffusion or through vascular tissues (xylem/phloem).
Major Plant Hormones and Their Functions:
Hormone Main Function
Auxin - Promoting cell elongation and phototropism.
Gibberellin - Aiding in stem growth and seed germination.
Cytokinin - Rapid cell division (especially in fruits and seeds).
Abscisic Acid - Inhibiting growth and causing leaf abscission (stress hormone).
Ethylene - A gaseous hormone that aids in fruit ripening.