Class 11 Chapter 13: Plant Growth and Development
Plant Growth and Development explains how plants grow, differentiate, and respond to internal and external factors throughout their life cycle. The chapter covers plant growth, growth phases, differentiation, dedifferentiation, redifferentiation, plant growth regulators (auxins, gibberellins, cytokinins, abscisic acid, and ethylene), photoperiodism, vernalisation, and seed dormancy. It is one of the most important chapters in Plant Physiology and carries significant weightage in NEET Biology, with questions frequently based on plant hormones, physiological responses, experiments, and NCERT concepts.
At ALLEN, these revision notes simplify Plant Growth and Development through concise explanations, NCERT-based facts, comparison tables, labelled diagrams, and exam-oriented revision points. These notes help students build conceptual clarity and prepare effectively for NEET and CBSE Board examinations.
1.0Chapter Snapshot
2.0Related Supporting Study Resources
3.0Learning Outcomes
After completing this chapter, you will be able to:
- Understand the phases and characteristics of plant growth.
- Explain differentiation, dedifferentiation, and redifferentiation.
- Describe the functions of different plant growth regulators.
- Differentiate between auxins, gibberellins, cytokinins, ethylene, and ABA.
- Understand photoperiodism and vernalisation.
- Analyze environmental factors affecting plant growth.
- Solve NCERT and NEET-based conceptual and application-based questions confidently.
4.05-Minute Quick Revision
Must-Revise Concepts
- Plant Growth
- Growth Curve
- Meristem
- Differentiation
- Dedifferentiation
- Redifferentiation
- Auxins
- Gibberellins
- Cytokinins
- Ethylene
- Abscisic Acid (ABA)
- Photoperiodism
- Vernalisation
- Seed Dormancy
Important NCERT Facts
- Plant growth follows a sigmoid (S-shaped) growth curve.
- Auxins promote cell elongation and apical dominance.
- Gibberellins stimulate stem elongation and break seed dormancy.
- Cytokinins promote cell division and delay leaf senescence.
- Abscisic acid (ABA) is known as the stress hormone and promotes dormancy.
- Ethylene accelerates fruit ripening and promotes senescence.
Diagram Recall
- Sigmoid Growth Curve
- Growth Phases
- Auxin Action
- Apical Dominance
- Photoperiodism
- Vernalisation
- Plant Growth Regulators
- Seed Germination
5.0Quick Revision Tips
- Memorize the functions of all five plant growth regulators.
- Compare plant hormones using a summary table.
- Revise photoperiodism and vernalisation together.
- Practice all NCERT diagrams and growth curves.
- Focus on hormone applications and physiological responses.
6.0High Weightage Topics
7.0NCERT Fact Box
8.0Common Mistakes & NEET Tips
9.0ALLEN Faculty Tips
- Prepare a comparison table of all five plant growth regulators.
- Memorize one major function and one application of each hormone.
- Revise photoperiodism and vernalisation together for better understanding.
- Practice the sigmoid growth curve and hormone-related diagrams.
- Focus on NCERT examples and physiological responses.
- Solve Previous Years' Questions (PYQs) and NCERT-based MCQs regularly.
10.0PYQ Trend Analysis
Plant Growth and Development is a high-weightage chapter in NEET Biology. Questions are frequently asked on plant growth regulators, photoperiodism, vernalisation, growth phases, and hormone functions.
Note: The trend below is based on the analysis of previous years' NEET question papers. The exact number of questions may vary each year.
11.0Most Common Question Types
- Identifying the functions of different plant growth regulators.
- Comparing auxins, gibberellins, cytokinins, ethylene, and ABA.
- Explaining photoperiodism and vernalisation.
- Solving questions based on growth phases and growth curves.
- Identifying the agricultural applications of plant hormones.
- Comparing differentiation, dedifferentiation, and redifferentiation.
- Answering NCERT-based assertion-reason and application-based questions.
- Solving Previous Years' NEET conceptual questions.
12.0Smart Revision Strategy
- Revise the phases of plant growth and the sigmoid growth curve.
- Memorize the functions and applications of all five plant growth regulators.
- Compare plant hormones using concise summary tables.
- Revise photoperiodism, vernalisation, and seed dormancy together.
- Practice all NCERT diagrams and flowcharts.
- Read NCERT examples and highlighted facts carefully.
- Solve Previous Years' Questions (PYQs) and NCERT-based MCQs.
- Complete revision with a chapter-wise NEET mock test.