Food Chain Trophic Levels YouTube Lecture Handouts

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Food Chain, Food Web and Ecological Pyramids - 3 Key Concepts in 1 Lecture

Food Chain Food Web Pyramids Bio-Magnification

This lecture explains what are food chains, food webs and ecological pyramids. She further explains the 3 types of ecological pyramids like pyramid of number, pyramid of biomass and pyramid of energy. She explains the possible cases including the upright and inverted pyramids.

Food Chain Food Web Pyramids Bio-Magnification Image-1
Food Chain Food Web Pyramids Bio-Magnification Image-2
Food Chain Food Web Pyramids Bio-Magnification Image-3

Pyramid of Number

  • Number of organisms at different trophic levels of food chain.
  • Successive links of trophic structure decrease rapidly in number.
  • Ignores biomass of organisms and energy transferred.

Pyramid of Biomass

  • Indicates decrease of biomass in each tropical level from base to apex.
  • Biomass of the producers is more than biomass of the herbivores

Pyramid of Energy

  • Energy pyramid indicates role of organisms in the transfer of energy.
  • Illustrates energy needed as it flows upwards.
  • Total energy small organisms assimilate and pass on, may be considerably greater than that of organisms with a much larger biomass.
  • Energy pyramids slope because less energy is transferred from each level than was paid into it
Number, Mass and Energy Pyramid Image
Food Chain Image-4
  • Bio-concentration
  • Bioaccumulation
  • Bio-magnification