Which of the following plant hormones regulates growth, particularly by stimulating cell elongation in stems?

Which of the following plant hormones regulates growth, particularly by stimulating cell elongation in stems? Correct Answer Auxin

The correct answer is Auxin.

Key Points

  • Stem Elongation
    • Stem elongation refers to the rapid growth in the length of the internodes of the upper stem before the reproductive phase starts for the plant.
    • Stem elongation causes many problems for the plant, such as skinny stems that are too weak to support large flowers, as well as plants that grow too high vertically and appear spindly, so it should be prevented.
  • Auxin
    • Auxin is a group of plant hormones that regulate growth, particularly by stimulating cell elongation in stems.
    • Auxins also play a role in cell division and differentiation, in fruit development, in the formation of roots from cuttings, in the inhibition of lateral branching and in leaf fall.
    • The most important naturally occurring auxin is ß- indolyl acetic acid (IAA).

Additional Information

  • Ethylene
    • Ethylene is the first-identified plant hormone known to regulate numerous processes in plant growth, development, and response to biotic and abiotic stresses.
    • Ethylene is best known for its effect on fruit ripening and thus has great commercial importance in agriculture.
  • Gibberellin
    • Gibberellin is a group of plant hormones that occur in seeds, young leaves, and roots.
    • It stimulates the growth of main stems, especially when applied to the whole plant.
    • It is commercially obtained from fungi.
  • Cytokinin
    • Cytokinins are plant hormones that influence not only numerous aspects of plant growth, development and physiology, including cell division.
    • Cytokinins are also produced by other prokaryotic and eukaryotic organisms such as bacteria, fungi, microalgae and insects.

Related Questions

In each question below is given a statement numbered I, II and III. An assumption is something supposed or taken for granted. You have to consider the following assumption and decide which of the assumption is implicit in the statement. Statement: The June 2018 quarter results of Infosys reflect that the investors waiting for the company to perform as good, if not better, than its largest peer Tata Consultancy Services (TCS) may have to wait a little longer. Infosys, the country’s second-largest software exporter reported slower sequential growth in revenue and profit than TCS for the June quarter (Q1). It also lagged on the fronts of employee attrition and growth in the banking, financial services, and insurance (BFSI) vertical.  Assumptions: I. On the positive side, Infosys continued to add large clients – four in the above $100-million billing category compared with the previous quarter. It continued to retain guidance of 6-8% revenue growth for FY19 while retaining the operating margin band of 22-24%. II. In the near term, the stock performance of TCS is likely to overshadow Infosys given the difference in their growth trajectories. III. The growth momentum of Infosys has slowed relative to TCS. The year-on-year growth in trailing 12-month (TTM) revenue of Infosys in each of the four quarters up to the June 2018 quarter has lagged TCS after leading in the previous five quarters.
Assertion (A) Hormones are also called growth adjusters.
Reason (R) Hormones promote or inhibit plant growth.
Which hormones are otherwise known as melanocyte stimulating hormones?