Question

This question consists of two statements, Assertion and Reason. While answering this question you are required to choose any one of the following five responses.

Assertion: Plant growth regulators (PGRs) are very important for plant growth and development.

Reason: Auxins do not induce flowering in gymnosperms.

Answer 1

Assertion-Reason relation
Plant growth regulators are the organic compounds responsible for signalling, control and regulation of plant growth. These are also known as phytohormones or plant hormones. Plant growth regulators can be divided into two types:

$\bullet$ Growth promoting regulators
$\bullet$ Growth inhibiting regulators

Hence, the given assertion- “Plant growth regulators (PGRs) are very important for plant growth and development” is true.

Auxin is a naturally occurring phytohormone which has plant growth promoting influences. Auxin is mainly found in the growing tips of plants like growing apices of roots and shoots etc.

Being a growth promoting phytohormone, it is mainly involved in growth promoting activities like root initiation, flowering initiation, cell enlargement, cell division etc.

Gymnosperms are vascular plants which possess naked seeds. These plants do not bear flowers. Therefore, auxin does not induce flowering in gymnosperms.

Hence, the given reason- “Auxins do not induce flowering in gymnosperms” is true but is not the right explanation of the given assertion.