71) Base pairing in DNA occurs through
A) covalent bonds between complementary bases on nucleic acid chains.
B) hydrogen bonds between complementary bases on nucleic acid chains.
C) salt bonds between complementary bases on nucleic acid chains.
D) an interaction that is not well understood.
72) Which of the following statements comparing DNA and RNA is correct?
A) DNA exists as a double helix of DNA chains; RNA is single stranded.
B) RNA exists as a double helix of RNA chains; DNA is single stranded.
C) Both DNA and RNA exist as a double helix.
D) Both DNA and RNA are single stranded.
73) Which of the following is NOT found in nucleic acids?
A) deoxyribose
B) glycerol
C) phosphate
D) thymine
74) Which of the following is NOT true for a DNA double helix?
A) Complementary base pairs are on the outside of the double helix.
B) Complementary base pairs are on the inside of the double helix.
C) The phosphate groups are on the outside of the double helix.
D) Each complementary base pair contains a pyrimidine and a purine.