Bio 151 Quiz #3

If a double-stranded DNA sample were composed of 30 percent guanine, what would be the percentage of adenine? (give the number only)

20

If a double-stranded DNA sample were composed of 10 percent thymine, what would be the percentage of guanine?

40

If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence ________.

5'TGCAAT3'

What part(s) of a nucleotide are always the same in DNA structure?

Phosphate and sugar

Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes?

The phosphodiester linkages of the polynucleotide backbone would be broken.

Which of the following includes all of the pyrimidines found in RNA and DNA?

cytosine

Which of the following best describes DNA's secondary structure?

double antiparallel helical strands