DNA polymerase is the answer. Hope it helps. Cheers mate
The early immune response to HIV-1 infection is likely to be an important factor in determining the clinical course of disease. Recent data indicate that the HIV-1 quasispecies that arise following a mucosal infection are usually derived from a single transmitted virus. Moreover, the finding that the first effective immune responses drive the selection of virus escape mutations provides insight into the earliest immune responses against the transmitted virus and their contributions to the control of acute viraemia. Strong innate and adaptive immune responses occur subsequently but they are too late to eliminate the infection. In this Review, we discuss recent studies on the kinetics and quality of early immune responses to HIV-1 and their implications for developing a successful preventive HIV-1 vaccine.
Answer:
The key difference between substrate and product is that substrate is the staring material of a chemical reaction whereas product is the compound obtained after the completion of the reaction. The terms substrate and product are used in spontaneous reactions and in reactions upon which an enzyme acts on as a catalyst.
Explanation:
A deciduous forest or a sandy beach