Question 1

Transcription factors function to help move ribosomes along the mRNA.

Accepted Answer

A) True 
 B)False  False

Question 2

Describe how the sigma subunit (factor)of E.coli RNA polymerase participates in transcription.

Accepted Answer

The sigma subunit may give specificity to the RNA polymerase and play a regulatory function.It may be involved in the recognition of initiation sites or promoters.

Question 3

When considering the initiation of transcription,one often finds consensus sequences located in the region of the DNA where RNA polymerase(s)binds.Which of the following is a common consensus sequence?

Accepted Answer

A)   TATA
B)   GGTTC
C)   TTTTAAAA
D)   any trinucleotide repeat
E)   satellite DNAs A

Question 4

What is a nonsense mutation?

Accepted Answer

The answer of What is a nonsense mutation?...

Question 5

Describe the direction of information flow in living systems.Use appropriate,scientific terms in your description.

Accepted Answer

The answer of Describe the direction of information flow in...

Question 6

What is one particular function that the codons (UAA,UGA,or UAG)serve during protein synthesis?

Accepted Answer

A)   UAA, UGA, and UAG are initiator codons, not termination codons.
B)   They allow the mRNA to assume a variety of linear conformations.
C)   These triplets cause frameshift mutations, but are not involved in termination.
D)   They provide a substrate for the addition of the initiator amino acid.
E)   They act in chain termination.

Question 7

The enzyme polynucleotide phosphorylase is capable of generating a random assembly of ribonucleotides.

Accepted Answer

A) True 
 B)False

Question 8

From the late 1950s to the mid-1960s,numerous experiments using in vitro cell-free systems provided information on the nature of the genetic code.Briefly outline significant experiments in the determination of the genetic code.

Accepted Answer

The answer of From the late 1950s to the mid-1960s,numerous...

Question 9

Significant in the deciphering of the genetic code was the discovery of the enzyme polynucleotide phosphorylase.What is this enzyme used for?

Accepted Answer

A)   manufacture of synthetic RNA for cell-free systems
B)   ribosomal translocation
C)   peptide bond formation
D)   production of ribosomal proteins
E)   degradation of RNA

Question 10

What is the initiator triplet in both prokaryotes and eukaryotes? What amino acid is recruited by this triplet?

Accepted Answer

A)   UAA; no amino acid called in
B)   UAA or UGA; arginine
C)   AUG; arginine
D)   AUG; methionine
E)   UAA, methionine

Question 11

When scientists were attempting to determine the structure of the genetic code,Crick and coworkers found that when three base additions or three base deletions occurred in a single gene,the wild-type phenotype was sometimes restored.These data supported the hypothesis that ________.

Accepted Answer

A)   the code is triplet
B)   the code contains internal punctuation
C)   AUG is the initiating triplet
D)   the code is overlapping
E)   there are three amino acids per base

Question 12

What two experimental procedures allowed deciphering of the ordered triplet assignments of the genetic code?

Accepted Answer

The answer of What two experimental procedures allowed deciphering of...

Question 13

A base at the first position of an anticodon on the tRNA would pair with a base at the ________ position of the mRNA.

Accepted Answer

The answer of A base at the first position of...

Question 14

Referring to the genetic code,what is meant by "wobble"?

Accepted Answer

The answer of Referring to the genetic code,what is meant...

Question 15

An intron is a section of an RNA that gets spliced out.

Accepted Answer

A) True 
 B)False

Question 16

A 5′-cap describes the addition of a base,usually thymine,to the 5′ end of a completed peptide.

Accepted Answer

A) True 
 B)False

Question 17

Suppose that in the use of polynucleotide phosphorylase,nucleotides A and C are added in a ratio of 1A:5C.What is the probability that an AAA sequence will occur?

Accepted Answer

The answer of Suppose that in the use of polynucleotide...

Question 18

In which cellular organelle do the three posttranscriptional modifications often seen in the maturation of mRNA in eukaryotes occur?

Accepted Answer

A)   nucleus
B)   cytoplasm
C)   mitochondrion
D)   lysosome
E)   Golgi

Question 19

Heterogeneous nuclear RNA is a primary transcript in eukaryotes that is processed prior to involvement in translation.

Accepted Answer

A) True 
 B)False

Question 20

Regarding the efficient initiation of transcription by RNA polymerase II,which specific "upstream" signals appear to be involved?

Accepted Answer

The answer of Regarding the efficient initiation of transcription by...

Exam 13: The Genetic Code and Transcription

Transcription factors function to help move ribosomes along the mRNA.

Describe how the sigma subunit (factor)of E.coli RNA polymerase participates in transcription.

When considering the initiation of transcription,one often finds consensus sequences located in the region of the DNA where RNA polymerase(s) binds.Which of the following is a common consensus sequence?

What is a nonsense mutation?

Describe the direction of information flow in living systems.Use appropriate,scientific terms in your description.

What is one particular function that the codons (UAA,UGA,or UAG) serve during protein synthesis?

The enzyme polynucleotide phosphorylase is capable of generating a random assembly of ribonucleotides.

From the late 1950s to the mid-1960s,numerous experiments using in vitro cell-free systems provided information on the nature of the genetic code.Briefly outline significant experiments in the determination of the genetic code.

Significant in the deciphering of the genetic code was the discovery of the enzyme polynucleotide phosphorylase.What is this enzyme used for?

What is the initiator triplet in both prokaryotes and eukaryotes? What amino acid is recruited by this triplet?

When scientists were attempting to determine the structure of the genetic code,Crick and coworkers found that when three base additions or three base deletions occurred in a single gene,the wild-type phenotype was sometimes restored.These data supported the hypothesis that ________.

What two experimental procedures allowed deciphering of the ordered triplet assignments of the genetic code?

A base at the first position of an anticodon on the tRNA would pair with a base at the ________ position of the mRNA.

Referring to the genetic code,what is meant by "wobble"?

An intron is a section of an RNA that gets spliced out.

A 5′-cap describes the addition of a base,usually thymine,to the 5′ end of a completed peptide.

Suppose that in the use of polynucleotide phosphorylase,nucleotides A and C are added in a ratio of 1A:5C.What is the probability that an AAA sequence will occur?

In which cellular organelle do the three posttranscriptional modifications often seen in the maturation of mRNA in eukaryotes occur?

Heterogeneous nuclear RNA is a primary transcript in eukaryotes that is processed prior to involvement in translation.

Regarding the efficient initiation of transcription by RNA polymerase II,which specific "upstream" signals appear to be involved?