Our environment

• Biodegradable wastes:

  • Wastes that can be broken down by biological processes
  • Mainly produced from plant and animal sources
  • Decomposed by enzymes released by microbes
• Non-biodegradable wastes:

  • Wastes that cannot be broken down by biological processes
  • Usually man-made like plastic, metal, etc.
• Waste management includes collection, transport, processing, and disposal of waste materials
• Measures for waste management:

  • Separate bins (blue and green) for non-biodegradable and biodegradable wastes
  • Reduction in the use of non-biodegradable products like plastic
  • Separation of materials for reuse or recycling
• 7 principles of solid waste management:

  • Reuse
  • Refuse
  • Recycle
  • Rethink
  • Reduce
  • Research
  • Regulation
  • Public awareness
• Ozone:

  • Protective layer of gas in the stratosphere
  • Ozone depletion mainly due to increased chlorine concentration
  • Chlorine mainly produced by chlorofluorocarbons (CFCs)
  • Ultraviolet light acts on CFCs in the stratosphere and releases chlorine atoms
  • Consequences of ozone depletion: skin darkening, skin cancer, aging, corneal cataracts, death of phytoplanktons
• Environment:

  • Natural surroundings and external conditions of an organism
  • Includes all living and non-living factors that affect the organism
• Components of an ecosystem:

  • Abiotic factors: non-living components like light, temperature, water, air, etc.
  • Biotic factors: living organisms
  • Autotrophs or producers: organisms that can manufacture their own food
  • Heterotrophs: organisms dependent on other organisms for food
  • Herbivores or primary consumers
  • Carnivores or secondary consumers
  • Omnivores
  • Decomposers
• Functions of an ecosystem:

  • Productivity: rate of production of organic matter by producers
  • Decomposition or recycling of nutrients: breakdown of organic matter with the help of decomposers
• Energy flow through an ecosystem:

  • Trophic level: level of species in an ecosystem based on the source of nutrition
  • Producers form the first trophic level
  • Food chain: linear sequence of organisms where each is eaten by the next
  • Food web: interconnected network of food chains
  • 10% law of energy transfer: only 10% energy transferred between trophic levels
  • Pyramid of energy: graphical representation of energy exchange in the ecosystem
  • Biomagnification: increase in concentration of pollutants with each step up in the food chain