If you begin with six cells, how many cells would you have after three rounds of division? if you begin with six cells, how many cells would you have after three rounds of division? twelve cells nine cells eighteen cells twenty-four cells forty-eight cells it is impossible to determine.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

the answer is d p: cell, q: organ, r: organ system, s: tissue