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Chapter Analysis
Intermediate13 pages • EnglishQuick Summary
The chapter on Control and Coordination explains how living organisms respond to environmental changes through various mechanisms. In animals, control and coordination involve the nervous system and hormones, facilitating responses like reflex actions, voluntary and involuntary actions. Similarly, plants use chemical signaling for movement and growth responses to stimuli such as light and gravity. This comprehensive study also outlines the structure and function of the nervous system, highlighting the roles of the brain, spinal cord, and hormones in maintaining homeostasis and adaptation.
Key Topics
- •Nervous system function and structure
- •Role of hormones in coordination
- •Reflex actions and voluntary responses
- •Phototropism and plant movement
- •Chemical signaling in plants and animals
- •Integration of body responses to stimuli
Learning Objectives
- ✓Understand how control and coordination occur in both plants and animals.
- ✓Identify the primary structures involved in the human nervous system.
- ✓Explain the role and function of hormones in regulating body processes.
- ✓Differentiate between voluntary and involuntary actions.
- ✓Demonstrate the concept of plant growth movements like phototropism.
- ✓Analyze the relationship between structure and function in the endocrine and nervous systems.
Questions in Chapter
How does chemical coordination take place in animals?
Answer: Chemical coordination in animals is facilitated by hormones, which are chemical messengers secreted by endocrine glands and carried through the bloodstream to different organs and tissues to regulate various functions.
Page 109
Why is the use of iodised salt advisable?
Answer: Iodised salt is advised because iodine is essential for the synthesis of the thyroid hormone, thyroxin, which regulates metabolism and is crucial for growth and development.
Page 111
How does our body respond when adrenaline is secreted into the blood?
Answer: When adrenaline is secreted into the blood, the heart beats faster, pumping more oxygen and nutrients to the muscles, preparing the body for a 'fight or flight' response.
Page 109
Why are some patients of diabetes treated by giving injections of insulin?
Answer: Insulin regulates the blood sugar level. In diabetes, the body either doesn't produce enough insulin or is unable to effectively use it, so insulin injections help manage blood sugar levels.
Page 111
Additional Practice Questions
Explain the role of the human brain in processing information and decision-making.
mediumAnswer: The human brain processes information with the fore-brain handling thoughts, the mid-brain managing sensory data processing, and the hind-brain maintaining balance and coordination. It integrates signals from the environment and internal organs to make informed decisions.
Describe how plants exhibit phototropism and why it is essential for their survival.
mediumAnswer: Phototropism in plants involves growth towards light, facilitated by the hormone auxin, which causes cells on the darker side of the plant to elongate. This growth is vital for maximizing photosynthesis, ensuring the plant receives sufficient energy from light.
Contrast the hormonal and nervous system control mechanisms in animals.
hardAnswer: The nervous system uses electrical impulses for fast, short-lived responses, while the hormonal system uses chemical signals for prolonged impacts affecting growth and metabolism. Both systems are integrated for comprehensive body regulation.
What is the advantage of having a reflex arc pathway in the nervous system?
easyAnswer: Reflex arcs provide a rapid response to stimuli without the delay of routing impulses through the brain, which is crucial for avoiding harm or danger efficiently.
How does adrenaline prepare the body for emergency situations?
mediumAnswer: Adrenaline increases heart rate and breathing, redirects blood to important muscles, and enhances alertness, preparing the body for quick physical actions in emergency scenarios.
NCERT Exemplar
AvailablePractice with NCERT Exemplar problems and solutions for this chapter. Exemplar problems are designed to help you master the concepts with advanced-level questions.
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