How can overharvesting of a single species, like beavers, affect an entire ecosystem?

Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work)

What is the mrna strand that would be copied from this dna strand

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point