Question

Assertion: Phytohormones are the plant compounds that can promote and inhibit the plant growth.
Reason: There are some phytohormones like auxin, cytokinins which play a role in plant growth and some phytohormones like abscisic acid which inhibit the plant growth.

• A. Both assertion and reason are true and the reason is the correct explanation of the assertion
• B. Both assertion and reason are true but the reason is not the correct explanation of the assertion
• C. The assertion is true but the reason is false
• D. Both assertion and reason are false

Answer 1

The correct option is A Both assertion and reason are true and the reason is the correct explanation of the assertion

Plant growth regulators are small, simple chemicals that control the growth and development of a plant. These are also termed as phytohormones or plant hormones. Phytohormones are involved in both growth promoting as well as inhibiting activities. Hence, assertion is correct.

On this basis, they are classified into two categories:
1. Plant growth promoter: Such plant growth regulators that are involved in plant growth-promoting activities like cell division, flowering, etc. are called plant growth promoters. For example, cytokinin, auxin, etc.
2. Plant growth inhibitor: The plant growth regulators that are involved in growth-inhibiting activities like dormancy (temporary inactive state of the cell), abscission (natural shedding of plant parts). For example, abscisic acid.
Hence, the reason is correct and is the correct explanation of the assertion.