18. Which of the following traits do archaeans and bacteria share? 1. composition of the cell wall; 2. presence of plasma membrane; 3. lack of a nuclear envelope 4. identical rRNA sequences. (A) 2 and 3 (B) 1 only (C) 3 only (D) 1 and 3 (E) 2 and 4

16. A principal problem with inserting an unmodified mammalian gene into a plasmid and then getting that gene expressed in bacteria is that _____. (A) bacteria translate only mRNAs that have multiple messages (B) prokaryotes use a different genetic code from that of eukaryotes (C) bacteria cannot remove eukaryotic introns (D) bacterial RNA polymerase cannot make RNA complementary to mammalian DNA

18. Which of the following traits do archaeans and bacteria share? 1. composition of the cell wall; 2. presence of plasma membrane; 3. lack of a nuclear envelope 4. identical rRNA sequences. (A) 2 and 3 (B) 1 only (C) 3 only (D) 1 and 3 (E) 2 and 4

其他試題

18. Which of the following traits do archaeans and bacteria share? 1. composition of the cell wall; 2. presence of plasma membrane; 3. lack of a nuclear envelope 4. identical rRNA sequences.
(A) 2 and 3
(B) 1 only
(C) 3 only
(D) 1 and 3
(E) 2 and 4