Bio102 Problems

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Bio102 Problems

Transcription and RNA Processing

1. In Eukaryotes, rRNA molecules are made by

A. RNA polymerase III.

B.

2

 ’ 

C. RNA polymerase I .

D. translation.

E. splicing.

2. The 3

ends of prokaryotic mRNA molecules are

A. polyadenylated.

B. capped.

C. spliced.

D. modified to make a Shine-Dalgarno sequence.

E. not modified.

3. The mRNA cap is an unusual structure because it

A. contains a deoxyribose sugar, that is usually only found in DNA.

B. has two purines base-paired together.

C. consistes of several hundred A nucleotides that are not found in the gene.

D. has two different matching anticodons.

E. contains three phosphate groups separating two sugars.

4. Unlike DNA polymerase, RNA polymerase

A. can synthesize a polymer.

B. can begin synthesis without a primer.

C. can add nucleotides to a 3

end.

D. does not require the strands to separate.

E. uses a DNA strand as a template.

5. In eukaryotic cells, the DNA strand that serves as a template for transcription is determined by

A. the origin of replication.

B. the terminator.

C. the snRNPs.

D. the start codon.

E. the promoter.

6. Which one statement is not true about DNA and RNA?

A. DNA contains deoxyribose and RNA contains ribose.

B. DNA contains T nucleotides and RNA contains U nucleotides.

C. Both DNA and RNA have a sugar-phosphate backbone.

D. Both DNA and RNA use the same purines.

E. DNA is always double-stranded and RNA is always single-stranded.

7. Splicing

A. happens only in humans and other mammals.

B. occurs at a faster rate due to enzymes called snRNPs.

C. allows crossing over during meiosis.

D. removes exons from an RNA molecule.

E. occurs in the cytosol.

8. The enhancers located near the albumin gene

A. are only present in liver cells.

B. bind transcription factors only found in the liver.

C. are located in introns.

D. change the position at which transcription begins.

E. need to be polyadenylated to be fully functional.

9. snRNPs facilitate what process?

A. Transcription

B. Translation

C. Splicing

D. Replication

E. Polyadenylation

10. Which one regulatory sequence is found in RNA (not DNA)?

A. Enhancer

B. Terminator

C. Origin

D. Promoter

E. Shine-Dalgarno sequence

11. Beadle and Tatum’s One Gene-One Enzyme hypothesis is not completely consistent with what form of regulation?

A. Multiple enhancers per gene

B. Polycistronic mRNAs

C. Alternative splicing

D. Polyadenylation

E. Steroid hormones

12. No template DNA exists for which sequence?

A. Introns

B. Poly A tails

C. Exons

D. Shine-Dalgarno sequence

E. UTRs (untranslated regions)

13. TFIID is only found in eukaryotes. What protein performs a similar function in prokaryotes?

A. Initiator protein

B. Sigma factor

C. Helicase

D. TFIIB

E. RNA polymerase II

14. Are each of the following statements about eukaryotic mRNAs true or false? Read carefully: a question is false unless it is completely true.

T

F

New sugar-phosphate bonds are created between exons during splicing.

T

F

The 5′ end of the mRNA is capped with a single G nucleotide using a 5′-to-5′ connection.

T

F

snRNPs are responsible for modifying the 3′ end of the mRNA.

T

F

Splicing allows for more than a single protein to be made from a single gene.

T

F

The start codon is located in the first intron.

T

F

The mRNA is synthesized by the enzyme RNA polymerase II in the nucleus.

15. For each of the following sequences, indicate if it is made of DNA, RNA or amino acids and then name the protein or complex that will bind to it.

Protein or complex that binds:

Shine-Dalgarno Sequence

TATA Box

-35 Box

DNA RNA amino acid Small subunit of the ribosome

DNA RNA amino acid TFIID

DNA RNA amino acid Sigma

Enhancer DNA RNA amino acid Transcription Factor

16. The removal of introns appears to “waste” a lot of cellular resources. What selective advantage is associated with splicing?

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