Exam 16: The Molecular Basis of Inheritance

In the polymerization of DNA,a phosphodiester bond is formed between a phosphate group of the nucleotide being added and which functional group of the last nucleotide in the polymer?

In E.coli,there is a mutation in a gene called dnaB that alters the helicase that normally acts at the origin.Which of the following would you expect as a result of this mutation?

Which of the following help(s)to hold the DNA strands apart while they are being replicated?

E.coli cells grown on ¹⁵N medium are transferred to ¹⁴N medium and allowed to grow for two more generations (two rounds of DNA replication).DNA extracted from these cells is centrifuged.What density distribution of DNA would you expect in this experiment?

What is a telomere?

Use the following information to answer the questions below. The green algae Chlamydomonas is said to be GC rich. -What does this mean?

Heterochromatin is observed in

In a linear eukaryotic chromatin sample,which of the following strands is looped into domains by scaffolding?

The images above are of DNA at various levels of coiling and folding.Use this image to answer the questions below. -For a science fair project,two students decided to repeat the Hershey and Chase experiment,with modifications.They decided to label the nitrogen of the DNA,rather than the phosphate.They reasoned that each nucleotide has only one phosphate and two to five nitrogens.Thus,labelling the nitrogens would provide a stronger signal than labelling the phosphates.Why won't this experiment work?

Eukaryotic telomeres replicate differently than the rest of the chromosome.This is a consequence of which of the following?

It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in which of the following?

Which of the enzymes removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of Okazaki fragments?

Grains represent radioactive material within the replicating eye. -In an experiment,DNA is allowed to replicate in an environment with all necessary enzymes,dATP,dCTP,dGTP,and radioactively labeled dTTP (³H thymidine)for several minutes and then switched to nonradioactive medium.It is then viewed by electron microscopy and autoradiography.The figure above represents the results. Which of the following is the most likely interpretation?

What is the basis for the difference in how the leading and lagging strands of DNA molecules are synthesized?

Which enzyme catalyzes the elongation of a DNA strand in the 5' → 3' direction?

After mixing a heat-killed,phosphorescent strain of bacteria with a living nonphosphorescent 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?

A biochemist isolates,purifies,and combines in a test tube a variety of molecules needed for DNA replication.When she adds some DNA to the mixture,replication occurs,but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long.What has she probably left out of the mixture?

In analyzing the number of different bases in a DNA sample,which result would be consistent with the base-pairing rules?

Which of the following investigator(s)was/were responsible for the following discovery? In DNA from any species,the amount of adenine equals the amount of thymine,and the amount of guanine equals the amount of cytosine.

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