Question

Flowering in pineapple is promoted by _______ .
(a) NAA
(b) $G{ A }_{ 3 }$
(c) Short days
(d) Cytokinin

Answer 1

Plant hormones (also known as phytohormones) are signal molecules that exist at extremely low concentrations and are formed within plants. A synthetic plant hormone in the auxin family promotes flowering in pineapple and is an ingredient in many commercial plants rooting horticultural products.

Complete answer:
A synthetic auxin that is produced is naphthalene acetic acid (NAA). It assists in the pineapple flowering process.
It is an organic compound that is soluble in organic solvents and is a colorless solid. It has a group of carboxymethyl connected to naphthalene's "1-position".
The hormone NAA does not occur naturally, and is toxic to plants at high concentrations, like all auxins. It is used for the vegetative propagation of plants from stem and leaf cuttings and is a rooting agent. It is also used for the tissue culture of plants.
Auxins, especially 1-naphthaleneacetic acid (NAA) and indole-3-butyric acid (IBA), are also widely used when cutting plants to stimulate root development.

Additional information: A group of chemicals that impact cell division and shoot formation are cytokinins or CKs. They also help delay tissue senescence, are responsible for mediating plant-wide auxin transport, and affect internodal length and leaf growth.
The hormone present in plants and fungi is gibberellic acid (also called gibberellin ${ A }_{ 3 }$, GA, and $G{ A }_{ 3 }$). Significant quantities of $G{ A }_{ 3 }$ are made by plants in their natural state. The hormone can be industrially developed using microorganisms. Gibberellic acid is a simple gibberellin, a diterpene pentacyclic acid that promotes cell growth and elongation.
So, the correct answer is, ‘NAA’.

Note: From embryogenesis, organ size regulation, pathogen protection, stress tolerance, and reproductive development, plant hormones regulate all aspects of plant growth and development.
Auxins are substances that have a beneficial effect on cell enlargement, development of buds and initiation of roots. They also stimulate the development of other hormones and regulate the growth of stems, roots, and fruits in combination with cytokinins, and turn stems into flowers. Auxins were the first class of discovered growth regulators.