NEET BIOLOGY

Detailed explanation-1: -These plant hormones include both natural and synthetic sources. Indole-3-acetic acid and indole butyric acid are obtained from natural plant sources, whereas naphthalene acetic acid and 2, 4-dichlorophenoxyacetic acid are obtained from synthetic sources.

Detailed explanation-2: -Plant growth regulators (PGRs) are natural or synthetic compounds with hormone-like activities. Like hormones, PGPRs act as chemical messengers for intercellular signaling and play a fundamental role in plant growth and development and response mechanisms to a wide range of abiotic and biotic stresses.

Detailed explanation-3: -Plants produce natural auxins such as Indole-3-acetic acid (IAA) and Indole butyric acid (IBA). Natural auxins are found in growing stems and roots from where they migrate to their site of action. Naphthalene acetic acid (NAA) and 2, 4-dichlorophenoxyacetic (2, 4-D) are examples of synthetic auxins.

Detailed explanation-4: -Indole-3-acetic acid or IAA is an auxin that occurs naturally and can also be artificially synthesized.

Detailed explanation-5: -Plant growth regulators are substances that, when added in small amounts, modify the growth of plants, usually by stimulating or inhibiting part of the natural growth regulatory system. Synthetic plant growth regu-lators hold the promise of becoming important tools in efforts to increase the world food supply.