Exam 16: The Molecular Basis of Inheritance

For a couple of decades, biologists knew the nucleus contained DNA and proteins. The prevailing opinion was that the genetic material was proteins, and not DNA. The reason for this belief was that proteins are more complex than DNA. What was the basis of this thinking?

Use Figure 16.1 to answer the following questions. Figure 16.1 -Once the pattern found after one round of replication was observed, Meselson and Stahl could be confident of which of the following conclusions?

Use Figure 16.1 to answer the following questions. Figure 16.1 -What determines the nucleotide sequence of the newly synthesized strand during DNA replication?

After mixing a heat-killed, phosphorescent strain of bacteria with a living non-phosphorescent strain, you discover that some of the living cells are now phosphorescent. Which observations would provide the best evidence that the ability to fluoresce is a heritable trait?

Which would you expect of a eukaryotic cell lacking telomerase?

Which of the following covalently connects segments of DNA?

If a cell were unable to produce histone proteins, which of the following would be a likely effect?

You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). These two classes of DNA probably represent

Which of the following synthesizes short segments of RNA?

When T2 phages infect bacteria and make more viruses in the presence of radioactive sulfur, what is the result?

The spontaneous loss of amino groups from adenine results in hypoxanthine, an uncommon base, opposite thymine in DNA. What combination of molecules could repair such damage?

Use Figure 16.1 to answer the following questions. Figure 16.1 -A space probe returns with a culture of a microorganism found on a distant planet. Analysis shows that it is a carbon-based life-form that has DNA. You grow the cells in ¹⁵N medium for several generations and then transfer them to ¹⁴N medium. Which pattern in Figure 16.1 would you expect if the DNA was replicated in a conservative manner?

Which of the following statements describes histones?

In his work with pneumonia-causing bacteria and mice, Griffith found that

Suppose you are provided with an actively dividing culture of E. coli bacteria to which radioactive thymine has been added. What would happen if a cell replicates once in the presence of this radioactive base?

Which of the following statements describes the eukaryotic chromosome?

Why do histones bind tightly to DNA?

The elongation of the leading strand during DNA synthesis

The difference between ATP and the nucleoside triphosphates used during DNA synthesis is that

What is meant by the description "antiparallel" regarding the strands that make up DNA?