Summary
Plant hormones, also known as plant growth regulators, play a crucial role in plant communication and growth processes such as elongation and germination.
- Auxin — a plant hormone that regulates elongation growth in roots and shoots. Example: Auxin (IAA) is synthesized in the growing tips of roots and shoots, aiding in cell elongation by water absorption.
- Gibberellin — a plant hormone involved in the germination of seeds like barley. Example: Gibberellin stimulates the production of amylase, which helps convert starch into maltose for energy during seed germination.
Exam Tips
Key Definitions to Remember
- Auxin: A plant hormone that regulates growth through cell elongation.
- Gibberellin: A plant hormone that aids in seed germination by stimulating enzyme production.
Common Confusions
- Confusing the role of auxin in elongation with its role in other growth processes.
- Misunderstanding the mechanism of gibberellin in seed germination.
Typical Exam Questions
- What is the role of auxin in plant growth? Auxin regulates elongation growth in roots and shoots.
- How does gibberellin affect seed germination? Gibberellin stimulates the production of amylase, which converts starch to maltose for energy.
- Which plant hormone is used commercially to speed up fruit ripening? Ethylene gas is used for this purpose.
What Examiners Usually Test
- Understanding of the mechanisms by which auxin and gibberellin function.
- Ability to explain the stages of seed germination involving gibberellin.
- Knowledge of commercial applications of plant hormones.