Example of artificial auxins are: (a) IPA (b) PAA (c) NAA (d) 2, 4, 5 – T (e) 2, 4 – D

Confusion Points
-Please note that there are 2 sets of information given in the Question .
-The first set (options a-e) mentions the names of compounds.
-The second set (options 1-4) mentions the combinations of first set of options.

🔑Key Points:
-Auxin refers to a group of plant hormones that regulate plant growth.

✏️Based on their origin, auxins can be divided into:
-Natural Auxins – They occur naturally in the plant and affect physiological functions. E.g. – IAA, IBA.
-Artificial Auxins – These are synthetically-derived chemical compounds that resemble IAA in biological activity. E.g. – NAA.
-Artificial auxins are widely used in horticultural practices, as weedicides, rooting agents and defoliating agents.

🛑Important Points:
-IPA
-Indole-3-pyruvic acid (IPA) is an intermediate in the IAA biosynthesis pathway.
-Hence, it is not an artificial auxin.
-PAA
-Phenylacetic acid (PAA) is a natural auxin.
-NAA
-Naphthalene acetic acid (NAA) is a artificial auxin that is used as a rooting agent.
-2,4,5-T
-2,4,5 – Trochlorophenoxyacetic acid is an artificial auxin that is used as a herbicide.
-2,4-D
-2,4 – Dichlorophenoxy acetic acid (2,4-D) is a artificial auxin that is widely used as a herbicide.