Question

1. why are fossil fuels considered to be non - renewable energy sources?

a. fossil fuels are constantly being made.
b. fossil fuels can be used up faster than they are made.
c. fossil fuels are cycled within a few years.
d. fossil fuels are able to reproduce to create more energy.

1. why does an energy pyramid get smaller at the higher levels?

a. there is less energy available for higher trophic levels.
b. there are fewer numbers of individuals at higher trophic levels.
c. there is more energy available for higher trophic levels.
d. both a and b are true

Explanation:

Question 16

Fossil fuels are formed over millions of years from organic matter. Option a is wrong as they aren't constantly made. Option c is wrong as they can't reproduce energy. Option d is wrong. Option b is correct because we consume fossil fuels (like oil, coal) faster than natural processes can form them (which take geological timescales, not a few years).

In an energy pyramid, energy is lost (as heat, for example) at each trophic level (about 90% loss, 10% transfer). So higher trophic levels have less energy available (option a is correct). Also, with less energy, the number of individuals (population) at higher levels is fewer (option b is correct). So both a and b make the pyramid smaller at higher levels, so option d is correct.

Answer:

b. Fossil fuels can be used up faster than they are made.

Question 17