If there are 100 units of energy available...?

Question

If there are 100 units of energy available in the grass level of the food chain grass → rabbit → coyote, how many units of energy would be in the coyote level?

a. 1 unit

b. 9 units

c. 10 units

d. 100 units

e. 1,000 units

Answer 1

d and e are clearly not the answer: d shows no energy losses and we know that's not possible and e shows an energy increase, which is again impossible.  So the issue is, how much of each input is lost during the transfer from one item to the next.  As you gave no indication of the fuel transfer efficiencies, this question cannot be answered.

One answer assumed energy efficiency e = O/I = energy out/energy in = 1/10.  I don't see that.  There is no biological reason I know of to assume the rabbit and coyote have the same efficiencies.  In fact, given the coyote is related to the canine species, which is notorious for its long sleeping pierods, I'd guess the rabbit's efficiency is higher than the coyote's.

Answer 2

I think it's 1

As the energy decrease by rate : 1/10

So grass : 100

rabbit : 10

coyote : 1

I'm not good in biology I suggest you ask this in biology.

Good luck

Answer 3

The answer is a. The rough approximation as you go up each trophic level is a 90% loss of energy.