Simplified Life Processes Short Notes Class 10

Life Processes Short Notes Class 10, is prepared strictly from your NCERT books of class 10 science chapter 5.

So , you can relay for your school as well as board exams

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Before you rush to memorise the short notes, may I request you to please read the Explanation of life processes, so that you can understand the chapter well.

If we undetstand something then it becomes very easy to memorise it.

Introduction: Life Processes

🧠 What Makes Something Alive?

1. 🔍 Observation

• 🐕 running, 🐄 chewing, 👨 shouting → alive
• 😴 sleeping but breathing → still alive
• 🌿 green plants → alive?
• 🌈 colored leaves → grows → alive

2. ⚠️ Visible Movement ≠ Enough

• ⛔ no visible growth/motion → maybe alive
• ✅ movement at molecular level = key

3. 🔬 Molecular Movement = Life

• 🔧 living = organised structure (tissues → cells → organelles)
• 🌍 environment breaks order
• 🔁 life = repair + maintain structure
• 🧱 structures = made of molecules → must move
• 🦠 virus = no movement until infection → debated status

📚 KEYWORDS & MEANINGS

WHAT ARE LIFE PROCESSES?

🧬 LIFE PROCESSES

Processes essential for the survival and maintenance of living organisms.

🔹 What are Life Processes?

• Continuous functions that maintain life, even at rest or sleep.
• Prevent breakdown of body structures.
• Require energy sourced from food (carbon-based molecules).

🔹 Main Life Processes

1. Nutrition

• Intake of food from external sources.
• Conversion of food into usable energy and raw materials.
• Process varies by organism and food complexity.

2. Respiration

• Breakdown of food to release energy.
• Involves oxidation-reduction reactions.
• Most organisms use oxygen for this process.

3. Transportation

• Movement of nutrients, gases (like oxygen), and waste across the body.
• Essential due to specialized tissues and large body sizes.

4. Excretion

• Elimination of toxic metabolic waste.
• Specialized tissues remove waste from different body parts.

🔹 Specialized Systems in Organisms

📘 KEYWORDS & TECHNICAL TERMS

Nutrition

🔹 NUTRITION – Life Process Overview

• Nutrition is the process of obtaining energy and materials from food.
• Required for growth, maintenance, and synthesis of essential substances.
• Even at rest, energy is needed to maintain internal order.

🔹 Why Is Nutrition Essential?

• ⚡ Provides energy for movement and internal functions.
• 🧱 Supplies raw materials for growth and repair.
• 🧬 Enables synthesis of proteins and other biomolecules.

🔹 Modes of Nutrition

1. Autotrophic Nutrition

• Organisms make their own food using inorganic substances.
• Use carbon dioxide + water to produce food via photosynthesis.
• Examples: Green plants, some bacteria.

2. Heterotrophic Nutrition

• Organisms consume complex organic substances.
• Food must be broken down into simpler forms using enzymes.
• Examples: Animals, fungi.
• Depend directly or indirectly on autotrophs for survival.

📘 KEYWORDS & TECHNICAL TERMS

Autotrophic Nutrition Study Short Notes

Overview of Autotrophic Nutrition

• Definition: Autotrophs produce their own food using photosynthesis.
• Key Process: Photosynthesis converts external substances into stored energy (carbohydrates).
• Raw Materials: Carbon dioxide (CO₂), water (H₂O).
• Requirements: Sunlight, chlorophyll.
• Energy Storage: Carbohydrates stored as starch for later use (similar to glycogen in humans).

Photosynthesis Process

Steps of Photosynthesis

1. Light Absorption:
   • Chlorophyll absorbs light energy.
2. Energy Conversion:
   • Light energy converted to chemical energy.
   • Water molecules split into hydrogen and oxygen.
3. Carbohydrate Formation:
   • Carbon dioxide reduced to carbohydrates.

• Note: Steps may not occur immediately one after another (e.g., desert plants store intermediates at night).

Essential Components for Photosynthesis

1. Chlorophyll

• Location: Found in chloroplasts (green dots in leaf cells under a microscope).
• Function: Absorbs light energy.
• Proof: Experiments show chlorophyll is essential for photosynthesis.

2. Carbon Dioxide

• Source: Enters through stomata (tiny pores on leaves, stems, roots).
• Exchange: Massive gaseous exchange via stomata for photosynthesis.
• Regulation:
  • Guard cells control stomatal opening/closing.
  • Swell with water → pore opens.
  • Shrink → pore closes to prevent water loss.

3. Sunlight

• Role: Provides energy for photosynthesis.
• Proof: Experiments demonstrate sunlight is essential.

4. Water

• Source: from soil by roots (terrestrial plants).
• Role: Split during photosynthesis to release hydrogen and oxygen.

5. Other Nutrients

• Nutrients: Nitrogen, phosphorus, iron, magnesium.
• Nitrogen:
  • Essential for proteins and compounds.
  • Absorbed as inorganic nitrates/nitrites or organic compounds (from bacteria).

Key Points to Memorize

• Photosynthesis Formula: CO₂ + H₂O + Sunlight → Carbohydrates + O₂.
• Starch: Stored energy reserve in plants.
• Stomata: Pores for gas exchange, controlled by guard cells.
• Chloroplasts: Contain chlorophyll for light absorption.

Heterotrophic Nutrition Study Short Notes

Overview of Heterotrophic Nutrition

• Definition: Organisms obtain food from external sources (plants, animals, or organic matter).
• Adaptation: Varies based on environment, food type, and availability.
• Key Factor: Food source (stationary like grass or mobile like deer) determines how food is accessed.

Types of Heterotrophic Nutrition

1. External Digestion

• Process: Food broken down outside the body, then absorbed.
• Examples:
  • Fungi (bread moulds, yeast, mushrooms).
• Mechanism: Enzymes secreted to decompose organic matter externally.

2. Internal Digestion

• Process: Whole food taken in and broken down inside the body.
• Depends On: Body design and digestive system.
• Examples:
  • Animals like humans, cows, lions.
• Note: What can be digested depends on organism’s anatomy.

3. Parasitic Nutrition

• Process: Derive nutrients from living hosts without killing them.
• Examples:
  • Plants: Cuscuta (amar-bel).
  • Animals: Ticks, lice, leeches, tapeworms.
• Strategy: Feed on host’s nutrients, often via specialized structures.

Key Points to Memorize

• Heterotrophic: Cannot produce own food, relies on external sources.
• Food Access: Varies by food mobility and organism’s adaptations.
• Strategies:
  • External digestion (fungi).
  • Internal digestion (animals).
  • Parasitic (living off hosts).
• Examples:
  • Stationary food: Grass → Cow.
  • Mobile food: Deer → Lion.
  • Parasitic: Cuscuta, lice.

How Organisms Obtain Nutrition Study Short Notes

Overview of Nutrition Acquisition

• Variation: Food type and acquisition method differ across organisms.
• Digestive System: Varies based on organism complexity.
  • Simple organisms: Use entire surface for food intake.
  • Complex organisms: Specialized parts for digestion.

Nutrition in Single-Celled Organisms

1. Amoeba

• Method: Uses temporary finger-like extensions (pseudopodia).
• Process:
  • Pseudopodia surround food, forming a food vacuole.
  • Complex substances broken down into simpler ones inside vacuole.
  • Simpler substances diffuse into cytoplasm.
  • Undigested material expelled from cell surface.
• Key Feature: No fixed food intake spot.

2. Paramoecium

• Method: Food taken in at a specific spot.
• Process:
  • Cilia (hair-like structures) move food to a fixed spot.
  • Food ingested and digested within the cell.
• Key Feature: Definite shape with cilia covering surface for food movement.

Key Points to Memorize

• Single-Celled Organisms:
  • Amoeba: Pseudopodia → Food vacuole → Digestion → Waste expulsion.
  • Paramoecium: Cilia → Fixed spot → Internal digestion.
• Complexity: As organisms evolve, digestion shifts from whole-surface intake to specialized structures.
• Food Vacuole: Temporary digestive compartment in Amoeba.
• Cilia: Hair-like structures in Paramoecium for food movement.

Nutrition in Human Beings Study Short Notes

Overview of Human Digestive System

• Alimentary Canal: Long tube from mouth to anus with specialized regions.
• Function: Breaks down complex food into small, absorbable molecules.
• Key Processes: Digestion, absorption, and waste elimination.

Digestive Process

1. Mouth

• Action: Food crushed by teeth, mixed with saliva.
• Saliva:
  • Secreted by salivary glands.
  • Contains salivary amylase (enzyme) → Breaks down starch into simple sugars.
• Tongue: Mixes food with saliva, aids chewing.
• Movement: Food moved to esophagus via peristalsis (rhythmic muscle contractions).

2. Esophagus

• Role: Transports food to stomach via peristaltic movements.
• Structure: Food pipe connecting mouth to stomach.

3. Stomach

• Action: Expands to hold food, mixes with digestive juices.
• Gastric Glands secrete:
  • Hydrochloric acid (HCl): Creates acidic medium, aids pepsin.
  • Pepsin: Digests proteins.
  • Mucus: Protects stomach lining from acid.
• Exit: Regulated by sphincter muscle releasing food to small intestine.
• Note: Acidity issues may relate to excess HCl.

4. Small Intestine

• Structure: Longest part, coiled for compact fit.
  • Length varies: Longer in herbivores (e.g., for cellulose digestion), shorter in carnivores.
• Function: Complete digestion of carbohydrates, proteins, fats.
• Secretions:
  • Liver: Produces bile → Emulsifies fats (breaks into smaller globules).
  • Pancreas: Secretes pancreatic juice with:
    • Trypsin: Digests proteins.
    • Lipase: Breaks down emulsified fats.
  • Intestinal glands: Secrete intestinal juice → Converts:
    • Proteins → Amino acids.
    • Carbohydrates → Glucose.
    • Fats → Fatty acids, glycerol.
• Absorption:
  • Villi: Finger-like projections increase surface area.
  • Rich in blood vessels → Transport nutrients to body cells for energy, tissue building, repair.

5. Large Intestine

• Role: Absorbs water from unabsorbed food.
• Waste: Remaining material expelled via anus, regulated by anal sphincter.

Key Points to Memorize

• Alimentary Canal: Mouth → Esophagus → Stomach → Small Intestine → Large Intestine → Anus.
• Enzymes:
  • Salivary amylase: Starch → Simple sugars.
  • Pepsin: Proteins (in stomach).
  • Trypsin, lipase: Proteins, fats (in small intestine).
• Bile: Emulsifies fats for easier digestion.
• Villi: Enhance absorption in small intestine.
• Peristalsis: Moves food through digestive tract.
• Anal Sphincter: Controls waste exit.

Respiration Study Short Notes

Overview of Respiration

• Purpose: Breaks down food (glucose) to release energy for life processes.
• Key Molecule: Glucose (6-carbon) → Pyruvate (3-carbon) in cytoplasm.
• Energy Storage: ATP (adenosine triphosphate) fuels cellular activities.
• Types:
• Aerobic Respiration: Uses oxygen, occurs in mitochondria, produces CO₂, water, and high energy.
• Anaerobic Respiration: No oxygen, produces less energy (e.g., ethanol in yeast, lactic acid in muscles).

Respiration Pathways

• Step 1: Glucose → Pyruvate (cytoplasm, all organisms).
• Aerobic Pathway:
• Pyruvate → CO₂ + H₂O (mitochondria, high energy).
• Anaerobic Pathways:
• Yeast: Pyruvate → Ethanol + CO₂ (fermentation).
• Muscles (low oxygen): Pyruvate → Lactic acid (causes cramps).
• ATP: Energy released stored in ATP, used for cellular reactions.

Gas Exchange in Organisms

Plants

• Structures: Stomata, large intercellular spaces.
• Process: Diffusion of O₂ and CO₂.
• Day: O₂ released (photosynthesis uses CO₂).
• Night: CO₂ released (no photosynthesis).
• Key: Direction of gas exchange depends on environmental conditions.

Animals

• Terrestrial: Use atmospheric O₂, have specialized organs (e.g., lungs).
• Aquatic: Use dissolved O₂ (low concentration, faster breathing rate).
• Example: Fish use gills to extract O₂ from water.

Respiration in Humans

Pathway

• Nostrils: Air filtered by hairs and mucus.
• Throat: Supported by cartilage rings to prevent collapse.
• Lungs: Air reaches alveoli via smaller tubes.
• Alveoli: Balloon-like structures for gas exchange.
• Rich in blood vessels.
• O₂ absorbed into blood, CO₂ released into alveoli.
• Breathing Mechanism:
• Inhalation: Ribs lift, diaphragm flattens, chest cavity expands → Air sucked in.
• Exhalation: CO₂ released, residual air remains for continuous gas exchange.

Oxygen Transport

• Respiratory Pigment: Haemoglobin (in red blood cells).
• High affinity for O₂, carries it to tissues.
• CO₂ Transport: Mostly dissolved in blood (more soluble than O₂).

Key Points to Memorize

• Glucose Breakdown: Glucose → Pyruvate → Aerobic (CO₂ + H₂O) or Anaerobic (ethanol/lactic acid).
• Aerobic: High energy, mitochondria, needs O₂.
• Anaerobic: Low energy, cytoplasm, no O₂ (e.g., yeast fermentation, muscle cramps).
• ATP: Energy currency for cells.
• Gas Exchange:
• Plants: Stomata, diffusion.
• Aquatic: Gills, fast breathing.
• Humans: Alveoli, haemoglobin transports O₂.
• Breathing: Inhalation expands chest; residual air ensures constant O₂ absorption.

Transportation in Human Beings Study Short Notes

Overview of Transportation

• Role of Blood: Transports food, oxygen, carbon dioxide, nitrogenous wastes, salts.
• Blood Composition:
  • Plasma: Fluid medium, transports food, carbon dioxide, nitrogenous wastes in dissolved form.
  • Red Blood Corpuscles: Carry oxygen via haemoglobin.
  • Platelets: Aid in clotting to minimize blood loss.
• System Components:
  • Heart: Pumping organ to push blood.
  • Blood Vessels: Network of tubes to reach all tissues.
  • Lymph: Fluid for fat transport and excess fluid drainage.

The Heart

• Structure: Muscular organ, size of a fist, four chambers.
• Chambers:
  • Left Atrium: Receives oxygen-rich blood from lungs.
  • Left Ventricle: Pumps oxygen-rich blood to body.
  • Right Atrium: Receives de-oxygenated blood from body.
  • Right Ventricle: Pumps de-oxygenated blood to lungs.
• Function:
  • Prevents mixing of oxygen-rich and de-oxygenated blood.
  • Valves: Ensure blood does not flow backwards during contraction.
  • Ventricles have thicker muscular walls than atria for pumping under pressure.
• Circulation:
  • Double Circulation: Blood passes through heart twice per cycle (lungs → heart → body → heart).

Blood Vessels

• Arteries:
  • Carry blood away from heart to various organs.
  • Thick, elastic walls to withstand high pressure.
• Veins:
  • Collect blood from organs, bring it back to heart.
  • Thin walls, contain valves to ensure one-direction flow.
• Capillaries:
  • Smallest vessels, one-cell-thick walls.
  • Enable exchange of material (oxygen, carbon dioxide, nutrients) between blood and surrounding cells.

Gas Exchange in Lungs

• Process: Oxygen enters blood, carbon dioxide released in alveoli.
• Pathway:
  • Oxygen-rich blood: Lungs → Left atrium → Left ventricle → Body.
  • De-oxygenated blood: Body → Right atrium → Right ventricle → Lungs.
• Efficiency: Separation of oxygen-rich and de-oxygenated blood supports high energy needs (e.g., birds, mammals).
• Comparison:
  • Amphibians/Reptiles: Three-chambered hearts, tolerate some mixing of oxygenated and de-oxygenated blood.
  • Fish: Two-chambered hearts, single circulation (blood passes heart once).

Maintenance by Platelets

• Role: Minimize blood loss by forming clots at points of injury.
• Mechanism: Platelet cells circulate, plug leaks, maintain pressure in the pumping system.

Lymph

• Definition: Tissue fluid (lymph) formed when plasma, proteins, and blood cells escape through pores in capillary walls into intercellular spaces.
• Composition: Colourless, similar to plasma but contains less protein.
• Functions:
  • Carries digested and absorbed fat from intestine.
  • Drains excess fluid from intercellular spaces back into blood.
• Pathway:
  • Lymph drains into lymphatic capillaries.
  • Lymphatic capillaries join to form large lymph vessels.
  • Large lymph vessels open into larger veins.

Key Points to Memorize

• Blood: Transports oxygen (via haemoglobin in red blood corpuscles), carbon dioxide, food, nitrogenous wastes, salts.
• Heart: Four chambers, double circulation, prevents mixing of oxygen-rich and de-oxygenated blood.
• Blood Vessels:
  • Arteries: High pressure, thick elastic walls.
  • Veins: Low pressure, valves for one-way flow.
  • Capillaries: Material exchange via thin walls.
• Lymph: Formed in intercellular spaces, drains into lymphatic capillaries → large lymph vessels → larger veins.
• Platelets: Clot blood to prevent leaks and maintain pressure.
• Double Circulation: Blood passes heart twice for efficient oxygen delivery.

Transportation in Plants Study Notes

Overview of Plant Transportation

• Purpose: Moves energy (from leaves) and raw materials (from roots) to support plant functions.
• Raw Materials: Nitrogen, phosphorus, minerals from soil; CO₂ for photosynthesis.
• Source: Soil (via roots), air (via leaves).
• Need for Transport: Diffusion insufficient for large plants; specialized systems required.
• Energy Needs: Low due to immobile nature and dead cells in tissues.
• Transport Systems:
• Xylem: Moves water and minerals from roots.
• Phloem: Transports photosynthesis products (e.g., sucrose) and other substances.

Transport of Water

• System: Xylem vessels and tracheids form a continuous water-conducting channel (roots → stems → leaves).
• Mechanism:
• Root Uptake: Root cells actively take up ions, creating a concentration gradient.
• Water moves into roots to balance ion concentration, forming a water column in xylem.
• Root Pressure: Pushes water upward (more significant at night).
• Transpiration:
• Loss of water vapor from aerial parts (via stomata).
• Creates suction (transpiration pull) to draw water from xylem in roots to leaves.
• Major driving force during the day when stomata are open.
• Functions:
• Transports water and dissolved minerals to leaves.
• Regulates plant temperature.

Transport of Food and Other Substances

• System: Phloem (sieve tubes and companion cells).
• Process: Translocation – Movement of soluble photosynthesis products (e.g., sucrose), amino acids, and other substances.
• Mechanism:
• Uses ATP energy to transfer materials (e.g., sucrose) into phloem.
• Increases osmotic pressure, causing water to enter phloem.
• Pressure drives materials to areas of lower pressure (e.g., storage organs, growing parts).
• Direction: Upward and downward, based on plant needs (e.g., sugar from roots to buds in spring).
• Destinations: Storage organs (roots, fruits, seeds), growing organs.

Key Points to Memorize

• Xylem: Transports water and minerals from roots using root pressure (night) and transpiration pull (day).
• Phloem: Translocates photosynthesis products (sucrose), amino acids using ATP-driven osmotic pressure.
• Transpiration: Water loss via stomata, drives water movement, regulates temperature.
• Translocation: Moves food to storage (roots, fruits, seeds) and growing organs.
• Roots: Absorb minerals and water from soil.
• Diffusion: Insufficient for large plants; xylem and phloem essential for transport.

Excretion Study Short Notes

Overview of Excretion

• Definition: Biological process of removing harmful metabolic wastes from the body.
• Types of Wastes:
• Gaseous: CO₂ (via respiration/photosynthesis).
• Nitrogenous: Urea, uric acid (via excretory system).
• Methods:
• Unicellular organisms: Simple diffusion across body surface into surrounding water.
• Multicellular organisms: Specialized organs for excretion.

Excretory System in Human Beings

• Components:
• Kidneys: Pair, located in abdomen on either side of backbone.
• Ureters: Tubes carrying urine from kidneys to bladder.
• Urinary Bladder: Stores urine until release.
• Urethra: Releases urine from bladder.
• Function: Filters nitrogenous wastes (urea, uric acid) from blood.

Urine Formation

• Process:
• Filtration: Occurs in nephrons (basic filtration units in kidneys).
  • Each nephron has a Bowman’s capsule (cup-shaped) with a cluster of thin-walled blood capillaries.
  • Blood filtered to form initial filtrate (contains waste, water, glucose, amino acids, salts).
• Selective Reabsorption: As filtrate flows through nephron tubes:
  • Glucose, amino acids, salts, and most water reabsorbed into blood.
  • Amount of water reabsorbed depends on body’s water and waste levels.
• Urine Collection: Final urine (waste + some water) enters ureters → urinary bladder.
• Storage and Release:
• Urine stored in muscular urinary bladder.
• Bladder expansion triggers urge to urinate via urethra.
• Urination under nervous control, allowing voluntary regulation.

Key Points to Memorize

• Excretion: Removes nitrogenous wastes (urea, uric acid) and excess water.
• Human Excretory System: Kidneys → Ureters → Urinary Bladder → Urethra.
• Nephrons: Filter blood in kidneys, contain Bowman’s capsule for filtration.
• Urine Formation: Filtration → Selective reabsorption → Urine collection.
• Bladder: Muscular, under nervous control for voluntary urination.
• Diffusion: Used by unicellular organisms; multicellular use specialized organs.

Excretion in Plants Study Notes

Overview of Excretion in Plants

• Definition: Removal of metabolic waste products from plant tissues.
• Key Difference: Unlike animals, plants lack specialized excretory organs.
• Wastes:
• Gaseous: Oxygen (from photosynthesis), CO₂ (from respiration).
• Liquid: Excess water.
• Other: Metabolic byproducts (resins, gums, etc.).
• Strategies: Utilize dead tissues, shedding parts, and diffusion into surroundings.

Excretion Mechanisms

• Gaseous Wastes:
• Oxygen: Waste from photosynthesis, released via stomata.
• Carbon Dioxide: Waste from respiration, released via stomata.
• Excess Water:
• Removed through transpiration (evaporation of water vapor from aerial parts, mainly leaves).
• Other Metabolic Wastes:
• Stored in cellular vacuoles (compartments within cells).
• Accumulated in dead cells (e.g., old xylem) as resins or gums.
• Stored in leaves that fall off, removing wastes from the plant.
• Excreted into the soil around roots.

Key Points to Memorize

• No Excretory Organs: Plants rely on diffusion, transpiration, and storage.
• Gaseous Wastes: O₂ (photosynthesis), CO₂ (respiration) released via stomata.
• Transpiration: Removes excess water through stomata.
• Storage Sites:
• Vacuoles: Store metabolic wastes.
• Dead Tissues: Old xylem stores resins, gums.
• Leaves: Wastes stored, removed when leaves fall.
• Soil Excretion: Some wastes released into surrounding soil.
• Dead Cells: Large proportion of plant tissues (e.g., xylem) used for waste storage.

Conclusion: Life Processes Short Notes Class 10

Well! If you have read so far then you must have realised that the Life Processes chapter is quite lengthy and full of technical words.

But,

with right mindset and zeal you can master it. Just keep revising it from your NCERT book and the contents that we have provide on this website. We will add more study tools and posts that will make to study less and score more.

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