What is the primary factor that determines if endocytosis or exocytosis would be needed to move a substance across the cell membrane as
opposed to diffusion or osmosis? *
- the chemical properties of the molecules being moved
- the differences in concentration of the substance inside and outside the cell
- whether water is being moved across the membrane
- the size of the molecules being moved

Match the following terms describing electrical events with the correct phases of the cardiac cycle. the ventricular muscle cells depolarize at the start of this phase. during this phase, na+ entry through the funny channels causes the pacemaker potential of sa nodal cells to gradually become less negative until it reaches threshold. the ventricular muscle cells repolarize right before this phase. the cytosolic concentration of calcium in the contractile cells of the ventricle is highest during this phase. a. isovolumetric relaxation b. ventricular ejection c. isovolumetric contraction d. ventricular filling

Adigestive system that is a series of tubes beginning at the mouth and ending at the anus is a digestive system.

Match each term to its best definition? sedimentary depositional enviornment