Which of the following statements is true?
a. the first vaccine was developed for cowpox.
b. before jenner's vaccine, there was no prevention for smallpox.
c. travelers to other countries are often required to get special vaccinations. d. missed immunizations cannot be given at future doctor visits.

Some viruses can be crystallized and their structures analyzed. one such virus is yellow mottle virus, which infects beans. this virus has a single-stranded rna genome containing about 6300 nucleotides. its capsid is 25-30 nm in diameter and contains 180 identical capsomeres.if the yellow mottle virus begins its infection of a cell by using its genome as mrna, which of the following would you expect to be able to measure? a) replication rateb) transcription ratec) translation rated) formation of new transcription factors