University of Central Florida FIL 1000 Ch

University of Central Florida

FIL 1000

Ch. 11 Quiz

1)A mutation in the lac A gene would result in Select one:

a.            continuous production of the proteins encoded by the three structural genes

b.            continuous production of the lac repressor

c.             normal operation of the lac operon, but with an alteration in the proteins encoded by the lac A gene

d.            no transcription from the lac operon

2.            Alternative splicing of exons is a mechanism to get more than 1 protein from the same gene. Select one:

a.            True

b.            False

3.            Consensus sequences are Select one:

a.            sequences that are invariant throughout the DNA.

b.            sequences required for transcription to occur c. sequences that have many bases in common

d. sequences that lie far upstream of the core promoter.

4.            How do eukaryotic and prokaryotic RNA polymerases compare? Select one:

a.            Since eukaryotic RNA polymerases are more complex, little homology has been found between the actual protein sequences in the catalytic subunits.

b.            Since eukaryotic transcription is less complex than in prokaryotes, monomeric RNA polymerases are used.

c.             Despite their added complexity, eukaryotic and prokaryotic RNA polymerases are generally homologous.

d.            Eukaryotic and prokaryotic RNA polymerases are virtually identical.

5.            Operons Select one:

a.            control the expression of constitutive genes. b. are subject to positive or to negative control.

c. are not affected by mutations in the genes for repressors or inducers.

d. occur in both prokaryotes and eukaryotes.

6.            TATA-binding protein (TBP) is normally required for transcription by Select one:

a.            Pol I.

b.            Pol II.

c.             Pol III.

d.            all of these polymerases.

e.            none of these polymerases

7.            The promoter site is Select one:

a.            the start site for transcription in DNA

b.            the binding site for regulatory proteins that stimulate transcription

c.             the general region of DNA downstream from the start site

d.            the site on DNA at which RNA polymerase binds to initiate transcription

e.            None of these

8.            The sequences in eukaryotic DNA known as introns are Select one:

a.            those included in the final sequence of messenger RNA

b.            the intervening sequences not expressed in the final sequence of messenger RNA

c.             the binding sites for DNA polymerase

d.            the binding sites for RNA polymerase

9.            Where is the TATA box located? Select one:

a.            At the transcription start site (+1).

b.            −10 region. c. −25 region.

d. −40 region.

10.          Which of the following is not true about RISC? Select one:

a.            It is only involved in cleaving dsRNA from viruses

b.            It is involved with processing of miRNA and siRNA

c.             It uses a protein from the argonaut family

d.            It unwinds dsRNA and eventually discards the passenger strand