PYQ NEET- Plant Growth And Development

2018:

The correct answer is (A) ABA.

ABA is a plant growth inhibitor. It inhibits seed germination, stem elongation, and leaf expansion.

GA and cytokinin are plant growth promoters. Ethylene is a plant growth regulator that can act as either a promoter or an inhibitor, depending on the concentration.

2017:

The correct answer is (D) Ethylene.

Ethylene is a gaseous plant growth regulator. It is involved in a variety of developmental processes, including fruit ripening, abscission, and dormancy.

Auxin, cytokinin, and gibberellin are all plant growth hormones. They are not gaseous.

2016:

The correct answer is (B) Cytokinin.

Cytokinin is a plant growth hormone that is involved in cell division and differentiation. It is not a gaseous plant growth regulator.

Ethylene, ABA, and GA are all gaseous plant growth regulators.