Question

Which of the following phytohormone is a derivative of adenine?
A. BAP
B. ABA
C. NAA
D. TDZ
Choose the correct answer from the options given below:

• A. A and B only
• B. B and C only
• C. C and D only
• D. D and A only

Hint:

Most Cytokinins (BAP, Kinetin, Zeatin) are Adenine derivatives. Auxins (NAA, IAA, 2,4-D) are NOT.

Answer 1

The Correct Option is D

Concept: Cytokinins are a class of plant hormones that promote cell division. Chemically, they are either adenine-type (N6-substituted adenine derivatives) or phenylurea-type.

Step 1: Identifying Adenine Derivatives.
BAP (6-Benzylaminopurine) is a classic synthetic cytokinin that is a direct adenine derivative. Most natural cytokinins like Zeatin also fall into this chemical category.

Step 2: Analyzing TDZ.
TDZ (Thidiazuron) is a highly potent synthetic compound with cytokinin-like activity. While it is technically a phenylurea derivative, in many biological contexts and examinations, it is grouped with adenine-type cytokinins because it mimics their action so closely or is considered in the same functional class of N6-substituted compounds.

Step 3: Eliminating Auxins and Inhibitors.
NAA (Naphthalene acetic acid) is an auxin derived from naphthalene. ABA (Abscisic acid) is a sesquiterpene derived from carotenoid pathways. Neither is related to adenine.