Exam 2 Review
Supplemental Instruction
IowaStateUniversity / Leader: / Matt C.
Course: / Biol/Gen 313
Instructor: / Dr. Rodermel
Date: / 10/12/2017

Introduction: The chapters to be covered by this exam are 2,9, 10, and 11.

The exam is going to be a mixture of multiple choice and short answer, but these questions are tough enough that multiple choice will be a sufficient challenge. Work through my worksheets or problems out of the book for more short answer practice.

Multiple Choice

  1. A mutation knocks out expression of DNA gyrase in E. coli. What is the likely effect this would have?
  2. DNA replication would be strongly inhibited or stopped due to supercoiling.
  3. RNA transcription would be strongly inhibited or stopped due to supercoiling.
  4. DNA replication would be strongly inhibited or stopped due to the lack of ability to split hydrogen bonding between complementary bases.
  5. RNA transcription would be strongly inhibited or stopped due to the lack of ability to split hydrogen bonding between complementary bases.
  6. None of the above would happen.
  1. Telomerase activity helps solve which problem?
  2. Telomere dissociation.
  3. Base mismatch during DNA synthesis.
  4. Eukaryotic end-replication issues.
  5. Binding of the spindle apparatus during cell division.
  6. None of the above.
  1. A eukaryotic organism doesn’t add licensing factors during the G1 phase, but skips over the G1 checkpoint to begin DNA replication in S phase. What is likely to occur?
  2. The genome will be over-replicated.
  3. No DNA replication will occur.
  4. DNA replication will be completed, but with many more mutations than usual.
  5. Chromosomes will shorten following replication.
  6. None of the above.
  1. What is the primary function of sigma factors?
  2. To identify promoter regions in bacteria and assist in transcription initiation.
  3. To improve transcription elongation speed.
  4. To provide a proof-reading mechanism to the transcription holoenzyme.
  5. To put together the other components of the RNA polymerase complex.
  6. None of the above.
  1. Poly-adenylation accomplishes what?
  2. Lengthens telomere sequences.
  3. Creates a tail on the 3’ end of mRNAs.
  4. Protects the 5’ end of DNA from degradation.
  5. Modifies histone complexes.
  6. Multiple of the above are true.
  1. Below is an image of a DNA and mature mRNA hybrid. How many introns are contained in the DNA gene sequence?
  1. 2
  2. 3
  3. 4
  4. 5
  5. This cannot be determined.

  1. Several mutations occur in the terminator region of a bacterial gene following the inverted repeats that switches out A bases for T bases. What is the likely effect of this change?
  2. If the gene is rho-dependent, it won’t be transcribed.
  3. If the gene is rho-independent, it won’t be transcribed.
  4. The gene won’t be transcribed regardless of its rho-dependency.
  5. The gene will be transcribed, but it will continue past the terminator until it reaches the next terminator.
  6. Gene transcription will not be affected significantly.
  1. Which of the following is not an activity of DNA polymerase I?
  2. 5’-3’ DNA polymerase.
  3. 3’-5’ DNA polymerase.
  4. 5’-3’ exonuclease.
  5. 3’-5’ exonuclease.
  6. Multiple of the above are not activities of DNA polymerase I.
  1. All of the following are requirements for transcription EXCEPT:
  2. Priming with RNA primase.
  3. Sufficient NTPs.
  4. A DNA template.
  5. The RNA polymerase complex.
  6. All of these are requirements for transcription.
  1. Studies have shown that the knockout of telomerase in eukaryotic organisms leads to premature aging and death, however; telomerase isn’t synthesized at all in bacteria. What is the best explanation for this?
  2. Bacteria only have one chromosome.
  3. Bacteria have a circular chromosome.
  4. Bacteria only have one origin of replication.
  5. Bacteria don’t age regardless of telomere length.
  6. Bacteria actually do synthesize telomerase to deal with telomere shortening.
  1. Which of these proteins acts first during DNA replication at one origin?

  1. DNA primase.
  2. DNA helicase.
  3. DNA polymerase III.
  4. DNA ligase.
  5. Multiple of the above act at the same time at one origin.

  1. DNA polymerases are quite accurate with just their 5’-3’ polymerase activity, but also have a proofreading mechanism to improve that accuracy further. What is the name given to this mechanism?
  2. 3’-5’ polymerase activity.
  3. 2’-hydroxyl phosphodiester bond cleavage.
  4. 5’-3’ exonuclease activity.
  5. 3’-5’ exonuclease activity.
  6. None of these are involved in proofreading.
  1. For a certain gene, the sequence of the non-template strand is 5’-ATTGACCTG-3’. What is the mRNA sequence without processing?

  1. 5’-UTTGUCCTG-3’
  2. 5’-TAACTGGAC-3’
  3. 5’-AUUGACCUG-3’
  4. 5’-UAACUGGAC-3’
  5. You cannot know from this information.

Match the given terms with their representation marked below. You can reuse terms.

  1. Template strand.
  2. Coding strand.
  3. Promoter.
  4. Terminator.
  5. 5’- end.
  1. An RNA that normally associates with telomerase has sequence UAUCCCCUAUCCCC. A mutation occurs that converts the sequence to UAUCCCCUGGCCCC. What will likely happen as a result of the mutation?
  2. Proteins that normally associate with the telomere after synthesis won’t be able to recognize the new sequence.
  3. Telomerase will not be able to reattach after one round of synthesis.
  4. Telomerase won’t be able to bind at all. No new synthesis occurs.
  5. Telomerase will target the wrong DNA strand.
  6. None of these will happen. Telomerase activity would proceed as normal.
  1. A certain gene sequence in the DNA template has three exon regions with two introns in between. Alternative splicing occurs and connects exon 1 to exon 3. What happens to exon 2?
  2. Exon 2 will form its own mRNA and be transcribed.
  3. Exon 2 will attach to the end of exon 3.
  4. Exon 2 will be degraded with the two introns.
  5. Exon 2 will be degraded separately from the two introns since it doesn’t have a branch point site.
  6. None of the above since this splicing can’t occur.
  1. Consider the following amino acid. What best describes its sidechain?
  1. Polar; uncharged.
  2. Polar; charged.
  3. Nonpolar; uncharged.
  4. Nonpolar; charged.
  5. This isn’t an amino acid.

  1. Which polymerase synthesizes the majority of Okazaki fragments in eukaryotes?

  1. Polymerase I
  2. Polymerase III
  3. Polymerase α
  4. Polymerase δ
  5. Polymerase ε

  1. What type of enzyme is DNA gyrase in bacteria?

  1. Helicase
  2. Topoisomerase
  3. Exonuclease
  4. Endonuclease
  5. Polymerase

  1. A certain pre-mRNA has six exons. Exon 3 contains structural components vital for protein function and is never spliced out. How many mature mRNA products can be made via alternative splicing that retain exon 3?

  1. 5
  2. 6
  3. 8
  4. 16
  5. None of these.

  1. What is the eukaryotic analog for SSB proteins?

  1. ORC
  2. Topoisomerase
  3. RPA
  4. FEN1
  5. None of these.

  1. Which of the following is not a feature of mature mRNA in plants, but was a feature of the pre-mRNA?

  1. Introns
  2. Exons
  3. 5’-mG cap
  4. Promoter sequence
  5. None of the above

  1. Some people are born with a condition called Leber congenital amaurosis (LCA) that results in eventual blindness. What causes this disease according to the text?
  2. An inherited disorder in which cone cells don’t proliferate.
  3. Inhibited rod cell development as a result of mutagenic compounds passing the placental barrier before birth.
  4. An in utero bacterial infection arising from low availability of synthetic antibiotics in developing areas.
  5. Inheritance of a non-active gene involved in chemical modification of Vitamin A.
  6. None of the above.
  1. What is the biological function of restriction endonucleases?
  2. Assist in recombination.
  3. Destroy viruses.
  4. Re-sectioning of blunt ends in double-strand break repair.
  5. Degrade undesired RNA transcripts
  6. None of the above – restriction endonucleases are artificially engineered and don’t exist naturally in the biological world.
  1. Which of the following is a palindromic sequence?
  2. 5’-ATTCCG-3’
  3. 5’-ATTAAT-3’
  4. 5’-ATTTTA-3’
  5. 5’-ATTATT-3’
  6. Multiple of the above.

A short peptide is shown below. Provide the following numbers.

  1. Amino acids used to make the peptide.
  2. R-groups present.
  3. Peptide bonds present.
  4. Hydrophobic R-groups.
  5. Polar and uncharged R-groups.
  6. Charged R-groups.
  1. Which of the following is an example of a ribonucleoprotein?
  2. U1
  3. Telomerase
  4. RNA polymerase
  5. Poly-A polymerase
  6. Multiple of the above
  1. What can prokaryotes do that eukaryotes cannot?
  2. Couple transcription and translation.
  3. Splice mRNAs.
  4. Use promoter consensus sequences.
  5. Degrade viruses.
  6. Multiple of the above.