In mammalian cells, the mRNA sequence elements that target the mRNA for rapid degradation are called:
A. AU-rich elements.
B. upstream open reading frames.
C. age responsive elements.
D. enhancers.
Which of the following is not an essential component of the bacterial initiation stage of translation?
A. mRNA
B. IF-2
C. ATP
D. N-formylmethionyl-tRNAfMet
Plasmids can carry genes that are useful to the host bacteria. These genes encode proteins that can extend the range of environments that can be exploited by the bacteria. Which of the following would be a benefit to the host bacteria?
A. a plasmid that confers sensitivity to antibiotics
B. a plasmid that protects the bacteria from the host animal's immune response
C. a plasmid that encodes an agent that facilitates tissue colonization
D. a plasmid that confers antibiotic sensitivity and protects against a host's immune response
E. a plasmid that protects against a host's immune response and facilitates tissue colonization
Transfection is:
A. the artificial introduction of viral DNA into a bacterial cell.
B. the artificial introduction of viral DNA into a eukaryotic cell.
C. the first step (attachment) of a viral infection using a recombinant virus.
D. facilitated by treatment of cells with calcium chloride and heat shock.
E. useful when recombinant DNA is not introduced via infection by a viral vector.
Allof the following evidence supports the RNA world hypothesisexcept:
A. RNA can function as a genome.
B. An RNA component of ribosomes catalyzes the synthesis of proteins.
C. RNA can serve a structural role.
D. RNA stabilizes membranes.
E. RNA regulates gene expression.