Which is a mechanical vector that injects recombinant dna directly into the nucleus of a host cell?
a)gene gun
b)micropipette
c)bacterial plasmid
d)viral phage

Which of the following statements best distinguishes a hypothesis from a theory? a. theories are hypotheses that have been proved. b. hypotheses are guesses; theories are correct answers c. hypotheses usually are relatively narrow in scope; theories have broad explanatory power. d. theories are proved to be true; hypotheses are often contradicted by experimental results.