Exam 5: Fundamental Molecular Genetic Mechanisms

In biology the central dogma refers to:

In eukaryotes,the circular structure of mRNA molecules undergoing translation serves to

You are studying polysomes and want to see if their numbers are actually increased in cells translating protein from an expressed retroviral oncogene.Which of the following methods are used to visualize these structures?

The base in the wobble position of a codon

When the CAU anticodon of a tRNAᴹᵉᵗ was modified to UAC,the anticodon for tRNAⱽᵃˡ,valine aminoacyl-tRNA synthetase recognized the altered tRNAᴹᵉᵗ and added valine rather than methionine to it.When the converse modification was made,the altered tRNAⱽᵃˡ containing a CAU anticodon (rather than UAC)was recognized and activated by methionine aminoacyl-tRNA synthetase.What do these data suggest about the mechanism by which aminoacyl-tRNA synthetases recognize their cognate tRNAs?

Thymine-thymine dimers are chemical adducts that develop in the DNA as a result of damage caused by which of the following?

The replication of DNA is quite complicated and requires the participation of many different enzymatic activities.These include an RNA polymerase (DNA primase)that synthesizes short segments of RNA,called primers,which are base paired to the DNA template.The 3´-OH ends of these RNA primers serve as initiation sites for the actual DNA polymerase activity.Obviously,DNA primase can synthesize polynucleotides without the benefit of a 3´-OH primer;indeed,it can catalyze the hydrolysis and subsequent linkage of two nucleoside triphosphates without the need for a complementary strand whatsoever.The short segments of RNA must be eliminated and replaced with DNA before replication can be completed.Why do you think that RNA,rather than DNA,primers are employed in the DNA replication process?

Which of the following techniques would you need to use in order to determine the size of the large and small ribosomal subunits in E.coli?

In humans,the ribosome responsible for translating proteins consists of which of following two subunits?

DNA replication begins at sequences called

Which of the following factors recognizes the UAG,UAA,and UGA codons?

What is the difference between lytic and lysogenic bacteriophages?

Which of the following structures interacts with ribosomes?

Which parts of the newly synthesized mRNA molecule do not transmit information for the synthesis of protein?

You have received a saliva sample from a group of veterinarians who think one of the dogs they are treating has rabies.Which of the following techniques would you use to determine not only if this sample contains viral particles,but how many viral particles are in the sample?

Which of the following lead(s)to a point mutation?

Polio virus affects only intestinal cells and motor neurons.By analogy to HIV,explain why only these particular cell types are susceptible to polio infection.

To incorporate radiolabeled nucleotides into newly synthesized DNA,researchers use α-phosphorus32-labeled nucleotides,in a DNA synthesis reaction,where the α denotes the position of the radioactive phosphate moiety.Explain why the α position and not the β or γposition is the best position for the radioactive group in these experiments.

When the circular double-stranded DNA of certain viruses is underwound,the DNA can twist back on itself and form:

Which of the following is not a constituent of deoxyribonucleotides?