Question: 106: Which of the following growth regulators is an adenine derivative?
(1) Auxin
(2) Cytokinin
(3) Ethylene
(4) Abscisic acid
Answer: Option (2)
Explanation:
Plant growth regulators are organic substances that influence various physiological processes in plants.
Cytokinins are a class of plant growth regulators that are chemically derived from adenine.
They possess an adenine ring structure with different side chains attached to it.
Examples of cytokinins include kinetin and zeatin, both of which are adenine derivatives.
Auxins are derived from indole compounds and are not related to adenine.
Ethylene is a simple gaseous hydrocarbon and does not have an adenine structure.
Abscisic acid is a terpenoid compound and is not an adenine derivative.
Therefore, the correct answer is Option (2).