Feeding Relationships Flashcards
What is a producer?
An organism that makes its own food.
What is a primary consumer?
An organism that feeds on producers.
What is a secondary consumer?
An organism that feeds on primary consumers.
What is biomass?
The dry mass of all of the living organisms in an area.
Why is dry mass used for biomass?
Because the wet mass varies as the volume of water in the organism varies.
How do you calculate the efficiency of biomass transfer?
efficiency = (energy transferred / total energy available) × 100
Why are biomass transfers not 100% efficient?
Energy is lost through
- Egestion (removal of faeces)
- Excretion (removal of waste products e.g. urine)
- Respiration
- The production of inedible bones and shells
How does the efficiency of biomass transfers affect the number of trophic levels in a biomass pyramid?
The less efficient the transfers, the fewer trophic levels and the fewer organisms in higher trophic levels.
What is the difference between a food web and a food chain?
Food webs show the interactions of multiple different food chains. Food chains show one path of food dependencies.
