Exam 14: Dna Structure, Replication, and Organization

In the Meselson-Stahl experiment, bacterial DNA was labeled completely with heavy nitrogen (¹⁵N) and then grown in the presence of light nitrogen (¹⁴N). When only mixed DNA was observed after ONE generation of growth in¹⁴N, what was the conclusion?

How are purines distinguished from pyrimidines?

When DNA is replicated, ____.

Describe what happens to the nucleosome during DNA replication.

Figure 14.1 The accompanying figure depicts the result of an experiment to determine how DNA replication occurs. Based on these results, it appears that after replication, each new DNA molecule contains ____.

When Hershey and Chase labeled viruses with radioactive phosphorus, they concluded that the virus injects DNA and not protein into its host because ____.

In DNA, the purines are ____.

Nucleic acids are long chains of ____.

Without proofreading, the rate of DNA replication errors in bacteria and eukaryotes is as high as one for every ____ nucleotides assembled.

Proofreading by ____ corrects errors that occur during DNA replication.

During DNA replication, nucleosomes must ____ ahead of the replication fork and ____ after DNA is replicated.

DNA ligase closes nicks between ____ by forming ____ bonds.

James Watson, Francis Crick, Rosalind Franklin, and Maurice Wilkins are recognized for their contributions to the discovery of the ____.

In humans, telomerase ____.

Telomeres are found ____.

Topoisomerase functions by ____.

DNA replication is said to be semiconservative because ____.

Suppose a DNA replication error is not corrected. After two cell divisions, how many of the four daughter cells contain this mutation (assuming that the mistake was never corrected)?