Deck 15: Rna Synthesis

Question 1

Genomic DNA that encodes proteins undergoes the process of _____ to produce _____.

A) transcription; mRNA
B) transcription; tRNA
C) translation; rRNA
D) translation; proteins
E) transcription; proteins

Answer 1

transcription; mRNA

Question 2

Which of the following is responsible for RNA splicing?

A) rRNA
B) miRNA
C) tRNA
D) siRNA
E) snRNA

Answer 2

snRNA

Question 3

Which of the following best describes the nucleic acid complex formed during RNA polymerization?

A) two DNA-RNA hybrids since both DNA strands are transcribed simultaneously
B) one DNA-RNA hybrid and one single stranded DNA
C) one DNA-RNA hybrid with the other DNA strand bound to an RNA molecule on
RNA polymerase
D) there is no interaction between the growing RNA and the DNA
E) none of the above

Answer 3

one DNA-RNA hybrid and one single stranded DNA

Question 4

Which of the following eukaryotic RNA polymerase is correctly paired with the type of RNA that it produces?

A) RNA polymerase III: tRNA
B) RNA polymerase I: rRNA
C) RNA polymerase II: mRNA from protein-coding genes
D) RNA polymerase III: small RNAs such as miRNA and snRNA
E) all of the above

Question 5

Separation of DNA into a single stranded region around RNA polymerase creates _____.

A) hybridized DNA
B) a transcription bubble
C) Z-DNA
D) DNA bound to single stranded binding proteins
E) none of the above

Question 6

How do the NTPs enter RNA polymerase?

A) base-paired with the incoming (downstream) DNA
B) with the incoming DNA but not base-paired with it
C) from the exit site, as the DNA leaves the enzymes, the NTPs move in the opposite
Direction
D) through a funnel-like channel sized just for NTPs
E) there is no specific way, any of the above routes are used

Question 7

What are the two metal ions found in the active site of RNA polymerase?

A) two Ca²⁺
B) a Ca²⁺ and a Zn²⁺
C) two Zn²⁺
D) a Zn²⁺ and a Mg²⁺
E) two Mg²⁺

Question 8

What is the approximate size of the DNA-RNA hybrid present inside the RNA polymerase?

A) 3 base pairs
B) 6 base pairs
C) 9 base pairs
D) 12 base pairs
E) 15 base pairs

Question 9

What is the region immediately upstream from the starting site for RNA polymerization called?

A) promoter
B) enhancer
C) initiator
D) consensus sequence
E) TF binding site

Question 10

An AT-rich region found in eukaryotic promoters is called the ______ box.

Question 11

TFIIH is a transcription factor that is responsible for forming the transcription bubble. For this reason, TFIIH is best described as a _____.

A) gyrase
B) ligase
C) helicase
D) endonuclease
E) single-strand binding protein

Question 12

TFIIB

A) is important to the activity of RNA polymerase II
B) binds to TBP during initiation of transcription
C) orients the polymerase complex, dictates the travel direction of the enzyme
D) dictates the strand to be copied
E) all of the above

Question 13

Coactivators, corepressors and some transcription factors can bind up to ___ base pairs from the transcriptional start site.

A) 25
B) 60
C) 100
D) 500
E) 1000

Question 14

Which transcription factor is required to aid RNA polymerase in the removal of an incorrect nucleotide incorporated into the growing RNA?

A) TFIIP
B) TFIIS
C) TFIIT
D) TFIIX
E) TFIIZ

Question 15

In prokaryotic transcription, what must be released for the switch from initiation to elongation to occur?

A) TFIIB
B) ADP following phosphorylation of the RNA polymerase C-terminal domain
C) regulatory subunit bound to the C-terminal domain
D) $\sigma$ subunit
E) the TATA-binding protein

Question 16

RNA polymerases have an error rate of about 1 in ____ bases incorporated, which is much ___ than DNA polymerases.

A) 100,000; higher
B) 100,000; lower
C) 10⁸; higher
D) 10^-8; higher
E) none of the above

Question 17

During termination, Rho acts as a _____.

A) polymerase
B) ligase
C) NTP hydrolase
D) single-strand binding protein
E) helicase

Question 18

Termination of some bacterial transcription requires the ______ factor.

Question 19

Amanatin at low concentrations would be most expected to disrupt

A) translation via disruption of the structure of the ribosome
B) translation via transfer of amino acids to the ribosome
C) transcription in prokaryotes
D) transcription of rRNAs
E) transcription of mRNAs

Question 20

Drugs important to AIDS therapy commonly attack retroviruses, since humans lack ___

Question 21

In eukaryotes, mRNAs are synthesized in the cell ______, whereas most translation occurs in
The ______.

A) nucleus, nucleosome.
B) nucleus, cytosol.
C) cytosol, nucleosome.
D) cytosol, nucleus.
E) nucleosome, cytosol.

Question 22

Which of the following modifications occurs to all eukaryotic mRNA?

A) addition of a poly(A) tail to the 3' end of the molecule
B) hydrolysis of the terminal phosphate from the 5' triphosphate end of the molecule
C) addition of GMP to the 5'end via a 5' to 5'linkage
D) methylation of the 2'hydroxyl on the first nucleotide of the molecule
E) all of the above

Question 23

What is the purpose of the poly(A) tail on eukaryotic mRNA?

A) binds to short poly(U) molecules forming duplex RNA that resists degradation
B) forms a stem loop to aid in transport to the cytosol
C) aids in transport to the lysosome for degradation once the ribosome is finished with it
D) binds to the poly(A) binding protein to prevent exonuclease activity
E) none of the above

Question 24

What protein/RNA complex is responsible for the removal of introns?

A) intronase
B) RNA processing complex
C) spliceosome
D) ribozyme
E) none of the above

Question 25

Reactions occurring within the spliceosome seem to be similar in various ways to

A) self-splicing class II introns
B) restriction endonucleases
C) DNA polymerase III proofreading
D) base excision repair
E) Both (A) and (B)

Question 26

With differential splicing, humans can produce approximately ___ as many proteins as their ___ genes.

Question 27

Which is involved in differential splicing?
I. exon skipping
II. RNase P endonuclease activity
III. alternative donor sites
IV. multiple poly(A) signals

A) I and II
B) I and IV
C) I, III and IV
D) I only
E) III only

Question 28

Which of the following allows a gene to give more than one viable protein product?

A) exon suppression
B) alternative splicing
C) use of RNA interference
D) frame shift mutations
E) action of the decapping enzyme

Question 29

Which of the following is the major factor in determining how quickly an mRNA is degraded?

A) overall length of the mRNA
B) degree of intron removal
C) how quickly the cap is removed
D) length of poly(A) tail
E) all of the above play a role

Question 30

Eukaryotic rRNA genes are transcribed and processed in the ______.

Question 31

The drawing below is needed to answer the following two questions

-This molecule is

A) pseudouridine
B) uridine
C) 5-methyl uridine
D) inosine
E) carboxymethylaminomethyl-2-thiouridine

Question 32

The drawing below is needed to answer the following two questions

-This molecule is found in

A) nascent mRNA
B) tRNA
C) rRNA
D) mature mRNA
E) all of the above

Question 33

The ___ regulates passage of molecules into and out of the nucleus.

Question 34

Which is NOT allowed through the nuclear pore complex (NPC)?

A) DNA
B) mRNA
C) tRNA
D) rRNA
E) deoxynucleotides

Question 35

NPC nucleoproteins are conserved between
I. membrane-associated pore-forming structures
II. clathrin proteins
III. tubulin proteins
IV. adaptin proteins

A) I only
B) II and IV
C) III only
D) I, II and III
E) I, II and IV

Question 36

Cargo to be imported into the nucleus through the NPC binds to is associated with

A) GTP
B) Ran-GDP
C) intranuclear filaments
D) importin
E) exportin

Question 37

Most Ran in the nucleus is bound to ___, and most Ran in the cytosol is bound to ___.

A) GTP; GDP
B) GDP; GTP
C) GDP; GDP
D) GDP; ATP
E) ADP; GTP

Question 38

Which class of RNA is transported through several mechanisms, requiring varied protein adaptors?

A) tRNA
B) rRNA
C) mRNA
D) miRNA
E) snRNA

Question 39

Ran

A) has GTPase activity
B) can be found in both the nucleus and the cytosol
C) can be bound to both GTP and GDP
D) binds importin and exportin
E) all of the above

Question 40

Nuclear pores are dynamic, varying with

A) type of cell
B) organism development
C) cell life cycle stage
D) significant cell growth
E) all of the above