Our Environment

• Ecosystem

  • Definition & Components
    • Biotic Components: Living organisms (Producers, Consumers, Decomposers)
    • Abiotic Components: Non-living physical factors (Temperature, Light, Rain, Soil)
  • Types of Ecosystems
    • Natural (Forests, Ponds, Lakes)
    • Artificial / Man-made (Crop fields, Aquariums)
  • Functional Units
    • Trophic Levels: Feeding positions in a food chain (Producer $\rightarrow$ Herbivore $\rightarrow$ Carnivore)
    • 10% Law: Only 10% of energy is transferred to the next trophic level
    • Biological Magnification: Accumulation of harmful chemicals at higher trophic levels

• Food Chains and Food Webs

  • Food Chain: Linear network of links in a food chain
    • Example: Grass $\rightarrow$ Grasshopper $\rightarrow$ Frog $\rightarrow$ Snake $\rightarrow$ Eagle
  • Food Web: Complex, interconnected network of multiple food chains

• Environmental Problems & Human Impact

  • Ozone Layer Depletion
    • Ozone ($O_3$) Molecule: Shields Earth from harmful UV radiation
    • Depletion Cause: Use of CFCs (Chlorofluorocarbons) used in refrigerators and aerosols
    • Consequence: Skin cancer, cataracts, damage to crops
  • Waste Management
    • Types of Wastes
      • Biodegradable: Broken down by biological processes (Peels, paper, wood)
      • Non-biodegradable: Not broken down easily (Plastics, glass, heavy metals)
    • Methods of Disposal
      • Landfills
      • Recycling
      • Composting
      • Incineration