Question

Why do higher trophic levels in most ecosystems

contain fewer organisms than lower trophic
levels?
A. Energy available for use to the highest trophic
level is small
B. Energy available for use to the lowest trophic
level is small.
C. Energy available for use to the highest trophic
level is large.
D. Energy available for use to the highest and
lowest trophic levels is the same.

Answer 1

A. Energy available to use in highest trophic level is small

Step-by-step explanation:

A is the correct answer because in trophic levels, 10% of the energy from the prior level is transferred to the proceeding level.

So for example, 100% of a plant's energy is transferred to its consumer, the consumer can only use 10% of the original amount of energy.

Then the second level consumer can only use 1% of the original amount of energy.

Then, the tertiary consumer can only use .1% of the original amount of energy.

This makes being a higher level consumer less energy efficient than being a lower level consumer, resulting in fewer higher trophic levels.

Answer 2

A.Energy available for use to the highest trophic level is small

Step-by-step explanation:

As you go up in the trophic levels, only about 10% of the energy gets transferred from one level to the next. For example, the plants can only harvest 1% of the Sun's energy. The primary consumer can only absorb 10% of the energy from the plant he eats, so .1% of the total energy. The secondary consumer can only absorb 10% of the energy he get from eating the primary consumer, so .01%, and so on and so forth. As we climb up the trophic levels, there is less energy available and therefore less organisms.