In order to infect a cell, a virus must *

a. inject its protein into the cell while the DNA remains attached to the host cell surface
b. have a specific protein on its surface that can bind to a specific receptor protein on the host cell
c. actively burrow through the cell wall or cell membrane of the host cell to reach the cell's nucleus
d. dissolve its own capsid in order to release its nucleic acid

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population.b) the separated population is small, and genetic drift occurs.c) the isolated population is exposed to different selection pressures than the ancestral population.d) different mutations begin to distinguish the gene pools of the separated populations.e) gene flow between the two populations is extensive.