Given a scientific question, generate a correct answer to it.

[EX Q]: Methanogens in their gut enable what process in cows?
[EX A]: digestion

[EX Q]: Harmful instances of what can result in errors in protein sequence that yield non-functional proteins?
[EX A]: mutation

[EX Q]: What is the percentage of production transferred from one trophic level to the next
[EX A]:
trophic efficiency