Ecology-Chapter 1

Card Set Information

Ecology-Chapter 1
2015-09-22 21:24:07

Grade-9 Science
Show Answers:

  1. Ecosystem
    a biological community of interacting organisms and their environment
  2. Sustainable ecosystem
    An ecosystem that is capable of resisting pressure and preserving a great diversity of organisms. Examples: rainforests, tropical grasslands.
  3. Biotic
    All the living or recently living parts of an ecosystem. Consists of plants, animals, microorganisms and fungi.
  4. Abiotic
    The non-living parts of the ecosystem that organisms need to survive. Consists of water, soil, air (oxygen), sun (light) and chemical nutrients.
  5. Lithosphere
    Earth's solid outer layer, includes the rigid crust and the upper mantle. It extends 100 km down from the surface and runs under oceans and continents. It is home to many microorganisms, plants, animals and fungi.
  6. Hydrosphere
    All the water on Earth, including lakes, oceans, and ground water.
  7. Atmosphere
    • The layer of gases above the Earth's surface.
    • Water vapor and carbon dioxide in the atmosphere absorb sunlight and retain the Sun's energy as heat, warming the planet to temperatures suitable for life.
    • The lower atmosphere contains oxygen which many organisms need to survive.
    • The higher atmosphere contains ozone which protects organisms in the biosphere from the sun's harmful ultra-violet radiation. 

  8. Biosphere
    The part of the planet including water, land and air, where living organisms exist.
  9. Nutrients
    chemicals that are needed by living things and are continually cycled through ecosystems.
  10. Eutrophication
    A process in which nutrient levels (nitrogen and phosphorus levels) in aquatic ecosystems increase pushing it beyond the normal nutrient cycle and sustainability. It causes algal blooms that blocks sunlight from reaching plants and reduces the amount of oxygen available to fish and other organisms, so they die.
  11. Photosynthesis
    A process that changes solar energy into chemical energy.

    Carbon dioxide+water in the presence of sunlight and using chlorophyll in the leaves produce glucose+oxygen gas.
  12. Trophic Level
    A category of organisms that is defined by how the organisms gain their energy. Levels in the food chain.
  13. Biomass
    The total mass of living organisms in a defined group or area. The mass of living cells and tissues that has been assembled by organisms using solar energy.
  14. Trophic efficiency
    a measure of the amount of energy or biomass transferred from one trophic level to the next higher trophic level.
  15. Bioaccumulation
    A process in which materials, especially toxins, are ingested by an organism at a rate greater than they are eliminated.
  16. Biomagnification
    The increase in the concentration of a toxin as it moves from one trophic level to the next.
  17. Cellular respiration
    • A process that releases energy from organic molecules in the presence of oxygen. 
    • Carbohydrates mostly.
    • Used by most living organisms E.g. humans, bacteria, plants.
    • Essential to life
    • Glucose+oxygen=carbon dioxide+water
  18. Fermentation
    A process that releases energy from organic molecules, especially carbohydrates, in the absence of oxygen.
  19. Greenhouse gases
    Atmospheric gases that prevent heat from leaving the atmosphere, thus increasing the temperature of the atmosphere.
  20. Greenhouse effect
    the warming of the Earth as a result of greenhouse gases, which trap some of the energy that would otherwise leave Earth.
  21. Acid precipitation
    Rain, snow, or fog that is unnaturally acidic due to gases in the atmosphere that react with water to form acids (nitric acid and sulfuric acid).