Biomass Transfer and Trophic Levels

The video explains biomass pyramids, which illustrate the biomass at each trophic level in a food chain. It discusses how biomass decreases as you move up the trophic levels due to energy loss, with only about 10% of biomass being transferred to the next level. The video outlines three main reasons for this inefficiency: not all parts of an organism are consumed, not all consumed parts are absorbed, and most absorbed nutrients are used for respiration rather than growth. It also covers how to calculate biomass transfer efficiency using specific examples.

What does a pyramid of biomass represent?

• The number of organisms at each trophic level

• The energy flow between trophic levels

• The total mass of living organisms at each trophic level

• The height of organisms at each trophic level

Which organism is a primary consumer in the given food chain?

• Hawks

• Grass

• Rabbits

• Snakes

Why do the bars in a pyramid of biomass get smaller as you go up the trophic levels?

• Because the total mass of organisms decreases

• Because the number of organisms increases

• Because the organisms get smaller

• Because the energy increases

What percentage of biomass is typically transferred to the next trophic level?

• 50%

• 20%

• 10%

• 5%

Which of the following is NOT a reason for biomass loss?

• Most nutrients are used for respiration

• Some parts of the prey are not absorbed

• All biomass is stored within the organism forever

• Organisms do not eat every part of their prey

Why might hawks not absorb all parts of the snakes they consume?

• They do not need all the nutrients

• They cannot break down certain parts like scales

• They prefer to eat only the flesh

• They store the parts for later use

What is the most important reason for biomass loss?

• Organisms store biomass for future use

• Organisms do not eat every part of their prey

• Some parts of the prey are not absorbed

• Most nutrients are used for respiration

What waste products are released due to respiration?

• Carbon dioxide and urea

• Sulfur dioxide and ammonia

• Nitrogen and methane

• Oxygen and water

How do you calculate the efficiency of biomass transfer?

• Divide the biomass transferred by the biomass available and multiply by 100

• Add the biomass transferred to the biomass available and divide by 100

• Multiply the biomass transferred by the biomass available and divide by 100

• Subtract the biomass available from the biomass transferred and multiply by 100

If 15 kilos of biomass is transferred to snakes from 144 kilos of rabbit biomass, what is the efficiency?

• 20.4%

• 15.4%

• 25.4%

• 10.4%