Question

Which of the following is not a synthetic auxin:
(a) 2,4-D
(b) IBA
(c) IPA
(d) IAA

Answer 1

As a regulator of numerous biological processes, it is a phytohormone that plays a central role in plant growth and development. In the mature nodules, a tryptophan pull was present and young roots may have served as a precursor to its development.

Complete step by step answer:
Phytohormones are growth promoters of auxins. Indoleacetic acid (IAA) is an auxin from a natural plant. Artificial auxins used as weedicides are 2, 4-D and 2, 4, 5-T. Also, naphthalene acetic acid (NAA) is a commonly used artificial auxin in agriculture.
The most popular naturally occurring plant hormone in the auxin class is indole-3-acetic acid. It is the most recognized of the auxins and has been the focus of extensive study by plant physiologists. IAA is an indole derivative which contains a carboxymethyl substituent.
IAA has several different effects, like all auxins, such as causing cell elongation and cell division with all resulting plant growth and development outcomes. On a larger scale, IAA acts as a signalling molecule essential for plant organ production and growth coordination.
So, the correct answer is ‘indoleacetic acid (IAA) ’.

Additional information: A synthetic auxin that has traditionally been used as one of the most effective herbicides to combat broadleaf weeds is 2,4-dichlorophenoxyacetic acid (2,4-D) . It also has a strong potential to increase storage life and fruit quality at the same time.
Indole-3-butyric acid, with the C12H13NO2 molecular formula, is a white to light-yellow crystalline solid. At atmospheric pressure, it melts at 125 ° C and decomposes before boiling. In the auxin family, IBA is a plant hormone and is an ingredient in many commercial horticultural rooting products for plants.

Note: IAA has many distinct effects, like all auxins, such as causing cell elongation and cell division with all resulting plant growth and development outcomes. On a larger scale, IAA acts as a signaling molecule essential for plant organ production and growth coordination.