Question

Genetic dwarfism can be overcome by
A. Gibberellin
B. Ethylene
C. Auxin
D. ABA

Answer 1

Hint: There are various plant hormones and they have specific functions. In addition, a hormone was discovered by the Japanese scientist Kurosawa in the fungi Gibberella fujikuroi.

Complete answer: Gibberellin – It is also known as gibberellic acid. It was discovered by the Japanese plant pathologist Kurosawa while studying the abnormal growth in the paddy plant. It was believed to be caused due to Gibberella fujikuroi fungus. Yabuta and Suruki obtained the extract. Gibberellin is the most common phytohormone. Gibberellin causes the bolting phenomenon. It is the sudden increase in the length of the stem during flowering. It is sprayed on several plants like sugarcane and grapes to promote the increase of the length of the internodes/stem and peduncle respectively. In grapes, the increase in the length of the peduncle causes a large size of grapes.
Ethylene – Ethylene is the first established plant hormone by Burg. It is the only hormone to be present in gaseous form at room temperature. It is the most used hormone in agriculture. Ethylene is responsible for the climacteric phenomenon. It promotes seed germination. It promotes horizontal growth and reduces the longitudinal growth in stems and leaves. It promotes femaleness and the formation of the abscission layer.
Auxin – It was discovered by several scientists like Charles Darwin and Francis Darwin, Boysen, and Tenson, A Paal, F W Went, etc. while working on different plants over different periods. Auxin has an acidic nature. It causes cellular elongation. It is also responsible for phototropism and geotropism. It causes apical dominance. Auxin promotes secondary growth. It is also used as a weedicide.
ABA – It is also known as Abscisic acid. ABA is also known as Dormin as it promotes seed dormancy. It is called the stress hormone of the plants as it is produced more during adverse conditions. It was discovered by Carns and Addicot from the unripened fruit of cotton. As it counteracts the effect of gibberellin, thus, also known as anti-gibberellin. ABA helps in stomatal closing. It promotes senescence.
Thus, genetic dwarfism can be overcome by using Gibberellin.
Hence, the correct answer is option (A).

Note: Some more physiological effects of gibberellin are that gibberellin is responsible for seed germination in cereals. It inhibits the formation of the abscission layer. It also promotes parthenocarpy. Gibberellin promotes maleness in plants and it promotes flowering in Long day plants.