Pyramids of biomass

• What do pyramids of biomass show?

  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?

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

  Secondary consumers
• What is the definition of biomass?

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

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

  Fewer snakes than rabbits exist
• What percentage of biomass 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
• What is the first reason why only 10% of biomass is passed on?

  Not all parts of the organism are eaten
• Why might some parts of the consumed organism not be absorbed?

  They can't be broken down properly
• What happens to the nutrients that animals absorb?

  Used for energy through respiration
• What are the waste products released by organisms?

  Carbon dioxide and urea
• How do you calculate the efficiency of biomass transfer?

  Efficiency = biomass transferred / biomass available
• What is the efficiency between snakes and rabbits if 15 kg is transferred?

  10.4%
• What is the efficiency between snakes and hawks if 1.6 kg is transferred?

  10.7%
• What are the main reasons only 10% of biomass is transferred between trophic levels?

  1. Not all parts of the organism are eaten
  2. Some parts are not absorbed
  3. Most nutrients are used for energy