What is the primary function of this body system?

Johnny rode his bike 4 blicks down the street to his friend's house once he got to his friend house and realized he could not cone out to play he turned aroubd and went back home.what is 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

All eukaryotic cells contain small bodies called

Which of these parts of the membrane large moecules pass through it ?