Question

Which of the following statements are correct?
a. Cytokinins suppress the synthesis of chlorophyll.
b. Auxins control apical dominance.
c. Gibberellins promote shoot elongation.
D. Abscisic acid enables the seeds to withstand desiccation.
A. a and b only
B. b and c only
C. a and c only
D. b, c, and d only
E. c and d only

Answer 1

Hint: Plant hormone plays an important role in the life cycle of a plant. There are various plant hormones such as- Auxin, Gibberellins, Abscisic acid, Ethylene, Cytokinins, Salicylic acid, Strigolactones, Brassinosteroids, and nitrous (nitric) oxide.

Complete answer: Cytokinins: Cytokinins (CK) are a class of plant growth substances (phytohormones) that promote cell division, or cytokinesis, in plant roots and shoots.
They are involved primarily in cell growth and differentiation, but also affect apical dominance, axillary bud growth, and leaf senescence.
Auxin: Auxin is essential for cell growth, affecting both cell division and cellular expansion.
Auxin concentration level, together with other local factors, contributes to cell differentiation and specification of the cell fate.
Auxins promote stem elongation, inhibit the growth of lateral buds (maintains apical dominance).
Gibberellins: Gibberellins (GAs) are plant hormones that regulate various developmental processes, including stem elongation, germination, dormancy, flowering, flower development, and leaf and fruit senescence.
Abscisic acid: Abscisic acid (ABA) is a plant hormone that has important roles in seed development and maturation, in the synthesis of proteins and compatible osmolytes.
It enables plants to tolerate stresses due to environmental or biotic factors, and as a general inhibitor of growth and metabolic activities.
ABA functions in many plant developmental processes, including seed and bud dormancy, the control of organ size, and stomatal closure.

So, the answer is D. b, c, and d only

Note: Metabolism provides the power and building blocks for plant life but it is the hormones that regulate the speed of growth of the individual parts and integrate these parts to produce the form that we recognize as a plant.