Pyramids of biomass

• What do pyramids of biomass show in a food chain?

  The biomass of each trophic level
• In the given food chain, what is the producer?

  Grass
• Who are the primary consumers in the food chain described?

  Rabbits
• What role do snakes play in the food chain?

  They are the secondary consumers
• What is the term 'biomass' defined as?

  The mass of living organisms
• What does the decreasing size of bars in a biomass pyramid indicate?

  The total mass of organisms decreases at higher trophic levels
• Why is the total mass of snakes lower than that of rabbits?

  There are fewer snakes than rabbits
• What percentage of biomass and energy is typically transferred to the next trophic level?

  About 10%
• What happens to most of the biomass and energy when one organism is consumed by another?

  It is lost or used by the organism
• What is one reason why not all parts of an organism are consumed?

  Some parts are inedible, like bones or teeth
• What happens to the parts of the organism that are not absorbed?

  They are excreted as feces
• Why do animals use absorbed nutrients primarily?

  To release energy through respiration
• What is the formula to calculate the efficiency of biomass transfer?

  Efficiency = (biomass transferred / biomass available) × 100
• If the biomass transferred to snakes is 15 kg and the biomass available from rabbits is 144 kg, what is the efficiency of biomass transfer?

  10.4%
• If the biomass transferred to hawks is 1.6 kg and the biomass available from snakes is 15 kg, what is the efficiency of biomass transfer?

  10.7%
• What are the main reasons why only 10% of biomass and energy gets passed on in a food chain?

  • Not all parts of the consumed organism are eaten
  • Some consumed parts are not absorbed and are excreted
  • Most absorbed nutrients are used for energy through respiration
• What are the three main types of consumers in a food chain?

  Primary, secondary, and tertiary consumers
• What does the biomass pyramid illustrate about energy flow in ecosystems?

  It shows the decreasing energy available at higher trophic levels