Question

3. If 1 billion calories of food are available to primary consumers in the ecosystem, approximately how many
calories are available to the tertiary consumers?

Answer 1

Answer:

1,000,000 kCal

Explanation:

For every level of the food chain you move up, only 10% of the calories that that level consumed actually move on because the rest are lost as heat.  So here's how I calculated the answer:

Producers --> Primary Consumer:

1,000,000,000 kCal  x  0.10  =  100,000,000 kCal

** I multiplied by 0.10 because only 10% of the 1 billion calories will actually move on.

Primary Consumer --> Secondary Consumer:

100,000,000 kCal  x  0.10  =  10,000,000 kCal

Secondary Consumer --> Tertiary Consumer:

10,000,000 kCal  x  0.10  =  1,000,000 kCal