Prepare for NEET Biology Plant Growth and Development (Growth Regulators) with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert help to examine auxins, gibberellins, cytokinins, ethylene, and ABA roles.
NEET Questions / Botany / Plant Growth and Development / Growth Regulators
A plant hormone promotes bolting in rosette plants and is also antagonistic to the effects of abscisic acid on alpha-amylase activity. This hormone also plays a key role in apical dominance. Which of the following hormones fits this description?
Gibberellin
Auxin
Cytokinin
Ethylene
Which PGR is most likely responsible for the phenomenon observed when a plant bends towards a light source, even if the light source is unidirectional and doesn't illuminate the entire plant?
Cytokinin
Gibberellin
Auxin
Abscisic Acid
Ethylene is unique among plant growth regulators due to its:
Ability to promote cell division
Role in seed dormancy
Gaseous nature
Synthesis in the root apical meristem
Which of the following combinations of plant growth regulators are antagonistic in their action on apical dominance?
Auxin and Gibberellin
Cytokinin and Ethylene
Gibberellin and Abscisic Acid
Auxin and Cytokinin
The 'Richmond-Lang effect', which refers to the delay of senescence in leaves by cytokinins, is primarily attributed to their influence on:
Ethylene production
Cell wall synthesis
Nutrient mobilization
Stomatal closure
Which plant hormone is primarily responsible for inducing dormancy in seeds and buds, enabling them to withstand unfavorable environmental conditions?
Gibberellin (GA)
Auxin (IAA)
Cytokinin (CK)
Abscisic Acid (ABA)
Which plant hormone promotes cell elongation and is involved in phototropism?
Gibberellin
Cytokinin
Abscisic acid
Auxin
Which hormone is primarily responsible for fruit ripening?
Auxin
Gibberellin
Ethylene
Cytokinin
Gibberellins are known to promote:
Leaf abscission
Fruit ripening
Stem elongation
Root inhibition