LIFE PROCESS - CLASS 10 NCERT CHAPTER

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Chapter 6: Life Processes – Summary (Pointwise)

1. What are Life Processes?

  • Life processes are the basic activities performed by living organisms to maintain their life.

  • Essential life processes include nutrition, respiration, transportation, and excretion.

  • These processes are essential for growth, development, and survival.

2. Nutrition

Definition: The process of obtaining and utilizing food for energy and growth.

Types of Nutrition:

  • Autotrophic Nutrition:

    • Organisms make their own food (e.g., green plants, some bacteria).

    • Process: Photosynthesis.

    • Raw materials: Carbon dioxide, water, sunlight, and chlorophyll.

    • Photosynthesis Equation: 


       * Stomata regulate gas exchange and transpiration.

  • Heterotrophic Nutrition:

    • Organisms depend on other organisms for food (e.g., animals, fungi).

    • Types:

      • Holozoic (e.g., humans): Ingestion, digestion, absorption, assimilation, egestion.

      • Saprophytic (e.g., fungi): Feed on dead matter.

      • Parasitic (e.g., leech): Feed on a host organism.

Human Digestive System:

  • Mouth: Ingestion, mechanical and enzymatic digestion (saliva contains amylase).

  • Oesophagus: Transports food via peristalsis.

  • Stomach: Acidic digestion, enzyme pepsin digests proteins.

  • Small Intestine: Major site of digestion and absorption (enzymes from liver and pancreas help).

  • Large Intestine: Absorbs water; forms feces.

3. Respiration

Definition: Process of breaking down glucose to release energy.

Types of Respiration:

  • Aerobic Respiration (with oxygen): Produces more energy.

    • Glucose → CO₂ + H₂O + Energy (ATP)

  • Anaerobic Respiration (without oxygen): Less efficient.

    • In muscles: Glucose → Lactic acid + Energy

    • In yeast: Glucose → Alcohol + CO₂ + Energy

Human Respiratory System:

  • Nasal cavity → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli

  • Alveoli: Tiny air sacs where exchange of gases occurs.

  • Mechanism: Inhalation (diaphragm contracts), Exhalation (diaphragm relaxes).

4. Transportation

In Humans:

  • Circulatory System:

    • Heart: Four chambers (2 atria, 2 ventricles), pumps blood.

    • Arteries: Carry oxygenated blood (except pulmonary artery).

    • Veins: Carry deoxygenated blood (except pulmonary vein).

    • Capillaries: Connect arteries and veins, site of exchange.

  • Double Circulation:

    • Blood passes twice through the heart in one complete cycle: pulmonary (heart–lungs–heart) and systemic (heart–body–heart).

    • Ensures separation of oxygenated and deoxygenated blood.

  • Blood Components:

    • Plasma: Liquid portion.

    • RBCs: Carry oxygen via hemoglobin.

    • WBCs: Immunity.

    • Platelets: Blood clotting.

  • Lymph: Fluid that drains into lymphatic vessels; returns proteins and fluids to blood, fights infection.

In Plants:

  • Transport of Water and Minerals: By xylem (unidirectional from roots to leaves).

  • Transport of Food: By phloem (bidirectional, from source to sink).

  • Transpiration: Loss of water vapor from leaves, creates suction pull aiding water movement.

5. Excretion

In Humans:

  • Excretion: Removal of metabolic wastes (especially nitrogenous waste like urea).

  • Excretory System Components:

    • Kidneys: Filter blood, produce urine.

    • Ureters: Carry urine from kidneys to bladder.

    • Urinary Bladder: Stores urine.

    • Urethra: Removes urine from body.

  • Nephron: Structural and functional unit of kidney.

    • Glomerulus: Filters blood.

    • Tubule: Reabsorbs useful substances; waste forms urine.

  • Urine Formation Steps:

    • Filtration → Reabsorption → Secretion

  • Regulation of Urine: Controlled by water balance and ADH hormone.

In Plants:

  • Excretion:

    • Wastes stored in vacuoles or excreted via leaves, bark, or roots.

    • Gaseous wastes released through stomata.

    • Some waste products stored as resins, gums, or oils.

6. Key Diagrams to Remember

  • Human digestive system

  • Human respiratory system

  • Human heart and circulatory system

  • Nephron structure

  • Cross-section of a leaf showing stomata



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LIFE PROCESS CHAPTER CLASS 10 NCERT

Life processes are the basic activities performed by living organisms to maintain their life..

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