Class 10 Science - TAMILNADU
Plant and Animal Hormones
The chapter 'Plant and Animal Hormones' in Class 10 Science (Tamil Nadu Samacheer Kalvi) explores chemical coordination and control systems in living organisms. Students will learn about phytohormones such as auxins, gibberellins, cytokinins, abscisic acid, and ethylene that regulate plant growth and development. The chapter also details the human endocrine system, including major glands like the pituitary, thyroid, adrenal, pancreas, and gonads, along with their secretions and target functions. Understanding these chemical messengers is vital for board exams, as questions frequently test the functions of specific hormones and deficiency disorders.
Start Learning FreeKey Concepts
Plant Hormones (Phytohormones)
Chemical compounds produced in plants that coordinate growth, development, and responses to environmental stimuli.
Auxins
Plant hormones responsible for cell elongation, apical dominance, and root initiation, discovered by F.W. Went.
Gibberellins
Hormones that promote stem elongation, bolting in rosette plants, and breaking dormancy in seeds and buds.
Endocrine Glands
Ductless glands in animals and humans that secrete chemical messengers called hormones directly into the bloodstream.
Insulin and Glucagon
Pancreatic hormones that work antagonistically to regulate blood glucose levels in the human body.
Feedback Mechanism
A self-regulating control system where the level of hormones in the blood regulates further secretion of that hormone.
Important Formulas
Board Exam Info
In the Tamil Nadu Samacheer Kalvi Class 10 Science board examination, this chapter typically carries around 6 to 8 marks. Questions frequently appear as 1-mark objective questions, 2-mark definitions, 4-mark matching or diagram-based questions on endocrine glands, and detailed 7-mark descriptive questions explaining plant hormone functions or major human endocrine disorders like diabetes.
Frequently Asked Questions
What is the difference between plant hormones and animal hormones?
Plant hormones (phytohormones) are synthesized in various tissues, act locally or long-distance, and regulate growth. Animal hormones are secreted by specialized endocrine glands, transported via blood, and target specific organs.
Why is the pituitary gland called the master gland?
The pituitary gland is called the master gland because its hormones control and regulate the secretions of all other major endocrine glands in the body.
What causes diabetes mellitus?
Diabetes mellitus is caused by the insufficient secretion of the hormone insulin from the beta cells of the pancreas, leading to high blood glucose levels.
Learn Plant and Animal Hormones with Your AI Tutor
10 different ways to study this chapter. Free for 3 chapters per day.
Lecture
Key Points
Interactive
Quiz
Flashcards