Class 10 Science Life Processes Notes

Class 10 Science Life Processes Notes

Introduction

  • Life processes are the essential activities that keep an organism alive.
  • Main life processes include: Nutrition, Respiration, Transportation, and Excretion.

1. Nutrition

  • Definition: Process of taking food, breaking it down, and absorbing nutrients.

Types of Nutrition

  1. Autotrophic Nutrition: Organism makes its own food.
    • Example: Plants via photosynthesis
    • Equation: 6CO₂ + 6H₂O + sunlight → C₆H₁₂O₆ + 6O₂
  2. Heterotrophic Nutrition: Organism depends on others for food.
    • Types:
      • Holozoic: Humans, animals (ingestion → digestion → absorption → egestion)
      • Parasitic: Tapeworms, leeches (live on host)
      • Saprophytic: Fungi, bacteria (feed on dead matter)

2. Respiration

  • Definition: Process of releasing energy from food.

Types of Respiration

  1. Aerobic Respiration: Uses oxygen
    • Glucose + O₂ → CO₂ + H₂O + Energy (ATP)
  2. Anaerobic Respiration: Without oxygen
    • Glucose → Lactic acid + Energy (in animals)
    • Glucose → Ethanol + CO₂ + Energy (in plants/yeast)

3. Transportation

  • Definition: Movement of substances like water, minerals, and food in the body.

In Humans

  • Circulatory system: Heart, blood, blood vessels
  • Blood components: RBC, WBC, Platelets, Plasma
  • Functions: Transport of oxygen, nutrients, hormones, and waste

In Plants

  • Xylem: Water and minerals (root → leaves)
  • Phloem: Food (leaves → other parts)

4. Excretion

  • Definition: Removal of waste products from the body.

In Humans

  • Excretory organs: Kidneys, lungs, skin, liver
  • Kidney function: Filtration, reabsorption, excretion (urine formation)

In Plants

  • Excretion through: Stomata, leaves, bark, and root secretion