6. Nucleotide bases and aromatic amino acids absorb light respectively at
A. 280 and 260 nm
B. 260 and 280 nm
C. 270 and 280 nm
D. 260 and 270 nm
7. The glycosidic bonds in DNA and RNA
A. connect the sugar to the base
B. can be hydrolyzed by OH- ion
C. stabilize Watson-Crick H-bonds
D. are free to rotate over about 180°
8. Nucleic acids can be analyzed experimentally by their
A. molecular weight
B. absorption of visible light
C. absorption of uv light
D. none of these
9. Thymidine
A. can participate in hydrophobic interactions due to its methyl group
B. is replaced by uracil in RNA
C. normally forms two hydrogen bonds with adenosine
D. all of the above
10. A nucleotide consists of
A. a sugar, a base and a phosphate
B. a sugar and a phosphate
C. paired bases
D. a sugar, a base and three phosphates