What theory encompasses the idea that living organisms today are made of cells and arise from preexisting cells?

Name the glands associated with human digestive system

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

What kind of bond is created by the attraction between atomic particles of opposite charge? ionic bond hydrogen bond covalent bond nuclear bond