C, as A,B, and D aren't true.
Summary. Enzymes are catalysts that, within the mild conditions of temperature, pH, and pressure of the cells, carry out chemical reactions at amazing high rate. They are characterized by a remarkable efficiency and specificity. Substrates are the substances on which enzymes act.
I believe that on the Naive B-cell the antibodies exist as transmembrane proteins. A naive b-cell is a type of b-cell that has not been exposed to an antigen. When exposed it becomes either a memory B cell or a plasma cell that secrete antibodies specific to the antigen that was originally bound.
An isotonic solution is a solution in which the amount of dissolved material is equal both inside and outside of the cell. Water still flows in both directions, but an equal amount enters and leaves the cell. Hope this helps. :)
Answer:
A scope built of two systems of lenses ... ==> Compound light microscope
Explanation:
