Comprehensive Chapter Summary - Control and Coordination Class 10 NCERT

Overview

• Chapter Purpose: Explains control/coordination in organisms. Links to life processes. Exam Tip: Focus on diagrams, activities, hormones. Expanded Relevance 2025: Neuroscience applications. Do You Know: Reflex arcs in sports. Figures: Neuron, reflex arc, brain, endocrine glands. Key Insight: Controlled movements essential. Conservation: Hormonal balance in ecosystems.
• Broader Implications: Response to environment, survival, health.

Introduction: Movement and Life

• Movements indicate life: Growth-related (seedling pushes soil) or non-growth (cat running, children swinging, buffaloes chewing).
• Association with life: Response to environmental changes (cat sees mouse).
• Advantage: Use changes for benefit (plants to sunshine, pleasure from swinging, better digestion).
• Protection: Detect/respond to stimuli (bright light, hot object) via movement.
• Controlled movement: Depends on trigger; requires recognition/coordination.
• Systems: Specialized tissues in multicellular organisms for control/coordination.

6.1 Animals – Nervous System

• Provided by nervous/muscular tissues (from Class IX).
• Detection: Specialized nerve cell tips (receptors) in sense organs (ear, nose, tongue).
• Examples: Gustatory (taste), olfactory (smell).
• Impulse generation: Dendritic tip chemical reaction → electrical impulse.
• Travel: Dendrite → cell body → axon → end (releases chemicals across synapse).
• Synapse: Gap; starts impulse in next neuron.
• Delivery: To muscles/glands.
• Neuron network: Conducts information via impulses.
• Parts: (i) Dendrite (acquire), (ii) Axon (travel), (iii) Axon end (chemical signal).

6.1.1 What Happens in Reflex Actions?

• Reflex: Sudden action without thinking (jump from bus, pull hand from flame, mouth watering).
• Control: Without conscious thought; quick response to environment.
• Example: Touching flame → think pain/burn → move hand (time-consuming).
• Thinking: Complex; many neuron interactions in brain (dense networks).
• Brain: Receives/integrates signals; sends to muscles.
• Problem: Time for burn if via brain.
• Solution: Reflex arc – simpler connection (heat-detecting nerves to muscle nerves).
• Location: Spinal cord (nerves bundle).
• Evolution: Quick; animals without complex thinking use; remains efficient.
• Sequence for bright light on eyes: Detect → reflex arc → response.

6.1.2 Human Brain

• Not only reflex: Thinking beings; spinal cord supplies info to brain.
• CNS: Brain + spinal cord; receive/integrate info.
• Voluntary actions: Decide (writing, talking, moving chair, clapping).
• Communication: CNS to body via PNS (cranial/spinal nerves).
• Brain design: Complex; parts for inputs/outputs.
• Regions: Fore-brain (thinking; sensory areas for hearing/smell/sight; association interprets; motor controls voluntary muscles; hunger center).
• Mid-brain/hind-brain: Involuntary (blood pressure, salivation, vomiting by medulla).
• Cerebellum: Precision/posture/balance (walking, riding, picking).

6.1.3 How Are These Tissues Protected?

• Brain: In bony box (skull); fluid-filled balloon for shock absorption.
• Spinal cord: Vertebral column (backbone; feel hard/bumpy).

6.1.4 How Does the Nervous Tissue Cause Action?

• Process: Collect/send/process/decide/convey to muscles.
• Muscle movement: Nerve impulse reaches → fibre changes shape/shortens.
• Mechanism: Special proteins change shape/arrangement via impulses.
• Muscle types: Voluntary/involuntary (differences from Class IX).

6.2 Coordination in Plants

• No nervous/muscles: Respond to stimuli (touch-me-not folds, seedling direction).
• Types: Growth-independent (quick leaf fold) vs growth-dependent (no movement if prevented).

6.2.1 Immediate Response to Stimulus

• Sensitive plant: Quick leaf movement; no growth.
• Detection: Touch point ≠ movement point; info communicated.
• Means: Electrical-chemical (no specialized tissue).
• Movement: Cells change shape via water amount (swell/shrink).

6.2.2 Movement Due to Growth

• Tendrils: Sensitive; contact side grows less → circles/clings.
• Tropic movements: Directional (towards/away stimulus).
• Phototropism: Shoots to light, roots away.
• Geotropism: Roots down, shoots up (gravity).
• Hydrotropism: To water; Chemotropism: Chemicals (pollen tube to ovule).
• Activity 6.2: Bean seeds bend to light; roots away.

6.3 Hormones in Animals

• Chemical transmission: For wide changes (fight/flight in squirrel).
• Adrenaline: From adrenals; to blood; heart faster, more O2 to muscles; reduce blood to digestion/skin; increase breathing.
• Endocrine system: Second control way.
• Activity 6.3: Identify glands (Fig. 6.7).
• Plant hormones: Control directional growth.
• Animal growth: Controlled (no directional like plants).
• Examples: Iodine for thyroxin (metabolism; goitre if deficient).
• Growth hormone: Pituitary; deficiency → dwarfism.
• Puberty: Testosterone (males), oestrogen (females).
• Insulin: Pancreas; diabetes if low (injections).
• Feedback: Regulates amount (e.g., insulin on sugar levels).
• Table 6.1: Hormones/glands/functions.

Key Themes

• Control: Nervous/hormonal.
• Reflex: Quick protection.
• Brain: Thinking/involuntary.
• Plants: Tropisms/hormones.
• Hormones: Chemical messengers.

Exercises Summary

• Focus: Expanded to 60 Q&A: 20 short (1M), 20 medium (4M), 20 long (8M) based on NCERT + similar.
• Project Idea: Model neuron; test plant responses. Group Activity: Reflex simulation.

Key Definitions - Biology Glossary

Essential terms; flashcards-ready.

Revision Tip: Match to functions/examples.

Questions & Answers - From NCERT (Class 10)

60 Q&A based on questions extracted from the NCERT. Categorized as 20 Short (1 Mark), 20 Medium (4 Marks), 20 Long (8 Marks). Answers tailored to mark allocation, based on content. Answers are displayed directly below each question.

Short Questions (1 Mark Each) - 20 Total

Medium Questions (4 Marks Each) - 20 Total

Long Questions (8 Marks Each) - 20 Total

Practice Tip: 1M: 2min; 4M: 5min; 8M: 12min; use diagrams/activities.

Key Quotes - Biology Insights

Memorable lines for essays.

Usage: Intro for long answers.

Textbook Activities - Hands-On Learning

NCERT tasks expanded.

Teacher Note: Safety first; link to concepts.

Indicators of Coordination - Key Metrics

Coordination in biology is the harmonious functioning of different parts of an organism to respond to stimuli and maintain homeostasis. Key indicators include:

• Response to Stimuli: Organisms detect and react to changes like light or heat. In animals, this is seen in reflexes; in plants, tropisms like phototropism show shoots bending to light.
• Integrated Function: Organs work together, e.g., nervous system coordinating muscle movement in humans for walking.
• Behavioral Adaptations: Actions like migration or dormancy indicate coordination for survival.
• Homeostasis Maintenance: Regulating internal conditions, such as blood sugar via insulin or water balance in plants via abscisic acid.

Indicator	Animal Example	Plant Example
Response Type	Reflex/voluntary (e.g., knee-jerk)	Tropism (e.g., roots to gravity)
Speed	Fast via nerves (milliseconds)	Slow via growth (hours/days)
Mechanism	Impulses/hormones (adrenaline rush)	Hormones (auxin distribution)
Protection	Withdrawal from pain	Leaf folding on touch

These indicators ensure survival by enabling adaptive responses. Mnemonic: Nervous Reflexes Help Plants Coordinate (Neuron, Reflex, Hormone, Plant, Coordination).

Factors Affecting Coordination - Key Influences

Factors impacting coordination in nervous and hormonal systems include internal and external elements that can enhance or impair responses.

• Environmental Stimuli: Light, temperature, chemicals influence responses; e.g., circadian rhythms affected by light in humans, drought triggering abscisic acid in plants.
• Genetic Factors: Mutations disrupt, like in multiple sclerosis (nerve demyelination) or hormone deficiencies causing dwarfism.
• Physical Damage/Trauma: Injuries to spine or glands impair signals; e.g., spinal cord damage causes paralysis.
• Developmental Stage/Age: Coordination develops in embryos; aging slows reflexes or reduces hormone production.
• Hormonal/Neurotransmitter Balance: Imbalances like low dopamine in Parkinson's affect movement; stress alters cortisol.
• Body Design/Health: Complex nervous systems in animals vs hormone-based in plants; diseases like diabetes disrupt insulin coordination.

These factors determine efficiency; e.g., iodine deficiency affects thyroid coordination. Figure Tip: Link to brain/endocrine diagrams.

Mechanisms of Coordination in Biology

Coordination involves nervous and hormonal systems in animals, hormonal in plants, enabling responses and homeostasis.

• Nervous in Animals: Electrical impulses via neurons (sensory to CNS to motor); synapses transmit chemically. Reflex arcs for quick actions; brain integrates for voluntary. E.g., human autonomic system regulates heart rate.
• Hormonal in Animals: Glands release hormones into blood for widespread effects; feedback loops regulate. E.g., hypothalamus-pituitary axis controls growth; adrenaline for stress.
• Plant Mechanisms: Hormones like auxin for tropisms (directional growth); gibberellins for elongation, cytokinins for division. E.g., auxin uneven distribution causes phototropism; abscisic acid for stress responses.
• Protection/Integration: Bony structures protect nerves; systems interact, e.g., nervous triggering hormonal release.

Expansion: Health implications like diabetes from hormonal imbalance.

Quick Revision - Biology Flashcards & Mnemonics

Revision Hack: Mnemonic for brain parts: Fore Most Humans Can (Fore-brain, Mid-brain, Hind-brain, Cerebellum). Practice diagrams; link activities to conclusions.