The Living Organisms — Characteristics and Habitats

• Organisms and Surroundings

  • Organism
    • Definition: Individual living beings
    • Examples: Plants, animals, microorganisms
  • Surroundings
    • Where organisms live
    • Provides food, water, air, and shelter

• Habitat and Adaptation

  • Habitat
    • Dwelling place or home
    • Provides biotic (living) components
    • Provides abiotic (non-living) components
  • Adaptation
    • Special features or habits
    • Helps survival in a specific environment
    • Result of gradual changes over thousands of years

• Types of Habitats

  • Terrestrial Habitats (Land)
    • Desert
      • Abiotic: Scarcity of water, high daytime temperature, cold nights
      • Plant adaptations: Stems store water, leaves modified into spines (e.g., Cactus)
      • Animal adaptations: Long legs, burrowing habits, concentrated urine (e.g., Camel, rats, snakes)
    • Mountain Regions
      • Abiotic: Very cold, windy, snow snowfall in winters
      • Plant adaptations: Cone-shaped trees, sloping branches, needle-like leaves (e.g., Pine, fir)
      • Animal adaptations: Thick skin/fur, snow shoes, strong hooves (e.g., Snow leopard, yak, mountain goat)
    • Grasslands
      • Abiotic: Open spaces, moderate rainfall
      • Animal adaptations: Speed, camouflage, strong teeth (e.g., Lion as predator, Deer as prey)
  • Aquatic Habitats (Water)
    • Oceans
      • Abiotic: Salty water, dissolved oxygen
      • Animal adaptations: Streamlined body, gills, blowholes (e.g., Fish, squid, octopus, whales, dolphins)
    • Ponds and Lakes
      • Abiotic: Freshwater, stagnant or slow-moving
      • Plant adaptations: Roots fixed in soil, floating leaves, submerged divided leaves (e.g., Lotus, hydrilla)

• Characteristics of Living Beings

  • Need for Food
    • Source of energy for growth and life processes
    • Plants make food via photosynthesis; animals depend on plants/other animals
  • Growth
    • Increase in size and maturity over time
    • Seen in both plants and animals
  • Respiration
    • Process of releasing energy from food using oxygen
    • Involves breathing (exchange of gases)
    • Special organs: Gills (fish), skin/lungs (frogs), stomata (plants)
  • Response to Stimuli
    • Changes in surroundings that make us react
    • Examples: Mimosa (touch-me-not) leaves closing, pupils contracting in bright light
  • Excretion
    • Removal of waste products from the body
    • Plants shed waste leaves/gums; animals excrete sweat, urine, etc.
  • Reproduction
    • Giving rise to young ones of their own kind
    • Modes: Seeds, eggs, giving birth to live young
  • Movement
    • Changing place or position
    • Animals move from place to place; plants move parts (e.g., sunflowers tracking the sun)
  • Lifespan
    • Living beings eventually die
    • Ensures continuity of life on Earth through reproduction