Why does your breathing rate increase when you exercise?

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

In the presence of oxygen, glycolysis is followed a. the krebs cycle b. lactic acid fermentation c. alcoholic fermentation d. photosynthesis

What is a dendrite and what does it do?