This system is difficult to work with because it has six different parameters, all of which affect the behavior of the system. However, each of them has a biological meaning. Write a brief explanation of what each parameter (r1, r2, d, j, w, h, k) means and specify the appropriate units for each one. (Assume that time is measured in years, so that for example, the units of N are "prey per year" and the units of P are "predators per year.")

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

Which mechanism of transport takes place when solute particles move from a region of high concentration to a region of low concentration? active diffusion isotonic osmosis

The backbone of the double helix has an alternating molecules. what do you call these alternating molecule?