Question

1. The gene regulation strategy referred to as attenuation is commonly, but not necessarily exclusively, associated with operons/genes encoding:

a.      catabolic enzymes such as ?-galactosidase

b.     constitutively expressed products.

c.       amino acid biosynthetic enzymes.

d.     products whose expression is also regulated by cAMP.

e.      transcription factors and other gene regulators.

2. A common example of a proto-oncogene product would NOT likely be:

a.      a factor used in the proper translation of mRNAs.

b.     a transcription factor.

c.      a receptor in the plasma membrane.

d.     a component of a signal transduction pathway.

e.       All of the above are common examples of proto-oncogene products.

3. 6-ethylguanine is formed in the DNA of a cell exposed to the alkylating agent EMS. If not repaired properly, the most likely result will be a mutation best describe as a/an:

a. frameshift.

b. transition.

c. transversion.

d.nonsense.

e. base “fall out”.

4. The addition of a single0 G nucleotide into the sequence encoding an ORF in an E. coli cell would likely (best) be classified as a/an ________ mutation.

A. nonsense

B. missense

C. silent

D.deletion

E.frameshift.

5. In eukaryotes, the 30 nm solenoid is commonly associated with:

A. Holliday structures.

B. higher level chromatin structure.

C. DNA repair.

D. replication forks.

E. chromsomal orgins.

6. An atom of an R-group of an amino acid that is part of the alpha chain of human hemoglobin interacts with the R-group of an amino acid in an associated beta chain. This is an example of:

a.      primary structure.

b.      secondary structure.

c.      tertiary structure.

d.     quaternary structure.

e.      One cannot tell until information about the type of bond formed is provided.

7. An example of a regulatory sequence in the human genome, which when a number of nearby examples are methylated leads to the associated gene being shut down (perhaps indefinitely), is:

a.      a telomere.

b.     a CEN sequence.

c.      retroposon.

d.     a SINE.

e.      CpG.

8. The phenomenon of gene conversion, as originally observed with the studies of fungi that possessed ordered asci of spores that often had 5/3 or 6/2 dark/light ratios, is the result of what process?

a.      mismatch repair

b.     DNA replication

c.      UV mutagenesis

d.     primer removal

e.      helicase action

Answer 1