Cells will not secrete IgA until the second time they are exposed to antigen. So total number making antibody should increase and number secreting IgA should stay the same at zero . Only those cells that have appropriate antibodies on their surface will respond to antigen. The number of cells that make the appropriate antibodies and therefore the number that can form clones will stay the same , as the choice of which antibody to make is already set before exposure to antigen. C. Best answer is increase or stay the same , but increase was ok too.
Pacemaker cells give the signal for myocardial cells to contract.
In this case, the myocardial cells will only contract in response to every other signal from the pacemaker cells, so the period from one contraction to the next will be longer. Then the next contraction will occur at the usual time, and the interval between heart beats will stay the same. The anion exchanger is needed to trade bicarbonate in the RBC for Cl - in the plasma. Inside the RBC, carbonic anhydrase converts the CO 2 to carbonic acid, which then forms bicarb and protons. The primary carrying capacity of the solution depends on the amount of hemoglobin present.