[Lec 6] Mastering Biology: Transcription II

Question 1

In the diagram below, the gray unit represents _____.

a. RNA
b. DNA
c. transcription factors
d. RNA polymerase
e. the promoter

Answer 1

d.

Question 2

In the diagram below, the green unit represents _____.

a. RNA
b. DNA
c. transcription factors
d. RNA polymerase
e. the promoter

Answer 2

e.

Question 3

In the diagram below, the two blue strands represent _____.

a. RNA
b. DNA
c. transcription factors
d. RNA polymerase
e. the promoter

Answer 3

b.

Question 4

Which of these correctly illustrates the pairing of DNA and RNA nucleotides?

a. GTTACG
CAATCG

b. GTTACG
CAAUGC

c. GTTACG
GTTACG

d. GTTACG
ACCGTA

e. GTTACG
UAACAU

Answer 4

b.

Question 5

The direction of synthesis of an RNA transcript is _____.

a. 1’ —> 5’
b. 5’ —> 3’
c. 1’ —> 3’
d. 3’ —> 5’
e. 2’ —> 4’

Answer 5

b.

Question 6

Rank the events of transcription that occur before the elongation phase begins. From first to last.

Answer 6

1. RNA polymerase binds the promoter
2. the closed complex forms
3. the closed complex transitions to the open complex around the start site of transcription-
4. the initial transcribing complex forms
5. repeated transcription of ~9 nucleotides occur
6. polymerase escapes

Question 7

Function of poly-A polymerase.

Answer 7

1. does not require a DNA template
2. adds up to 200 As to the 3’ end of the mRNAs

Question 8

Function of RNA polymerase.

Answer 8

1. incorporates all four NTPs for RNA
2. requires a DNA template

Question 9

Which of the following lists steps of mRNA production in eukaryotes in the correct order?

a. Transcription, 5’ cap addition, addition of poly-A tail, exon splicing, passage through nuclear membrane
b. 5’ cap addition, addition of poly-A tail, exon splicing, passage through nuclear membrane, transcription
c. Transcription, addition of poly-A tail, 5’ cap addition, exon splicing, passage through nuclear membrane
d. Transcription, 5’ cap addition, addition of poly-A tail, passage through nuclear membrane, exon splicing

Answer 9

a.

Question 10

Which of the following is characteristic of transcription in eukaryotes but not in prokaryotes?

a. A 5’ untranslated leader sequence
b. A 3’ untranslated trailer sequence
c. A single transcript may be transcribed and translated simultaneously.
d. Exon splicing

Answer 10

d.

Question 11

Which of the following best describe(s) the function of the 5’mRNA cap?
Check all that apply.

a. To protect the transcript from degradation
b. Termination of transcription
c. It provides a site for ribosome binding in the cytoplasm.
d. To provide a binding site for poly(A) polymerase

Answer 11

a,c

Question 12

Which of the following events does NOT occur after the transcription of poly-A signal sequences into mRNA?

a. addition of many adenine residues to the 3′ end of the mRNA
b. cleavage of the mRNA releasing it from the RNA polymerase
c. 5′ capping of the mRNA
d. degradation of the mRNA remaining associated with RNA polymerase by a 5′ → 3′ ribonuclease

Answer 12

c.