4.7.4.3 Transfer of Biomass

Question 1

How does the amount of biomass at each trophic level change?

Answer 1

• less biomass as you move up the trophic level
• not all food consumers by an animal is converted into biomass - this means biomass of the organism in the level above another will always be higher, as not all the organism can be consumed and converted into biomass

Question 1

How much energy do producers transfer for photosynthesis?

Answer 1

producers are mostly plants and algae which transfer about 1% of the incident energy from light for photosynthesis

Question 2

What % of biomass is transferred from each trophic level to the next?

Answer 2

only approx. 10% of biomass from each trophic level is transferred to the level above it

Question 3

Losses of biomass are due to:

Answer 3

• not all the ingested material is absorbed, some is egested as fasces (e.g. herbivores do not have all the enzymes needed to digest all the materials that they eat so it is egested instead)
• some absorbed material is lost as waste e.g. carbon dioxide and water in respiration and water and urea in urine
• large amounts of glucose is used in respiration

Question 4

How do you calculate the efficiency of biomass transfers?

Answer 4

(biomass transferred to the next level / biomass available at the previous level) x100

Question 5

How do losses of biomass affect the number of organisms at each trophic level?

Answer 5

because less biomass is transferred each time it is common to find fewer animals in the higher trophic levels