The answer to your question is 2
Answer:
If a stimulus to a neuron is great enough, ___<u>t</u><u>h</u><u>r</u><u>e</u><u>s</u><u>h</u><u>o</u><u>l</u><u>d</u>_____ is reached and an action potential is generated.
Your answer would definitely be D - Mitochondria. Mitochondria is the organelle that supplies all the energy for a cell. Hope I was helpful, have a good day! 8)
Exaptation
Explanation:
In this example, the lateral extensions that developed were meant for thermoregulation.
But these became sufficiently large to support gliding through the air and later on were used for flight.
Thus the structure assumed a function for which it was not meant and its original function shifted to a completely different dimension giving rise to modern insect wings. So we can say that this is an example of Exaptation.