BIO 340 Final
Exam Questions
and Complete
Answers Graded
A+
Denning [Date] [Course title]
,What type of bonds are formed between complementary DNA bases? - Correct Ans: Hydrogen Bonds
Which of the following forms the backbone of a polynucleotide chain? - Correct Ans: alternating sugar
and phosphate groups
Guanine and adenine are purines found in DNA - Correct Ans: true
What fraction of the nucleotides in a doubles-stranded DNA molecule are cytosine and thymine? -
Correct Ans: 50%
What is one difference between DNA replication in bacteria versus eukaryotes? - Correct Ans:
Eukaryotic chromosomes have many origins of replication, while bacteria have only one origin of
replication
What is the maximum rate between DNA replication in E. coli - Correct Ans: 1000 nucleotides
During DNA replication in E. coli, what is the role of DnaA? - Correct Ans: DnaA bends DNA, hydrolyzing
the hydrogen bonds in the 13-mer region of otic and creating an open complex
Which of the following statements about DNA replication is true? - Correct Ans: Single-strand binding
proteins stabilize the open conformation of the unwound DNA
Which of the following reagents is not required for the polymerase chain reaction? - Correct Ans:
Dideoxynucleotide triphosphate
Which of the following would you find in a Sanger sequencing reaction but not in a polymerase chain
reaction? - Correct Ans: ddNTPs
Which of the following statements about ddNTPs is true? - Correct Ans: they have a hydrogen at the 3'
carbon of the sugar
,The principles of complementary base pairing and antiparallel polarity of nucleic acid strands is a duplex
are universal for the formation of nucleic acid duplexes. What is the chemical basis for this university? -
Correct Ans:
You wish to create a mutation in which you prevent access of RNA polymerase to the gene. Which
region of a gene would you target? - Correct Ans: promoter sequence
Which region(s) of a gene are not found within the mRNA transcript? - Correct Ans: promoter region
Which of the following statements regarding Nucleotide Excision repair (NER) and Base Excision Repair
(BER) is true? - Correct Ans: both NER and BER involve the removal of one or more damaged bases by a
nuclease
How large is an origin of replication of E. coli? - Correct Ans: 245 base pairs
Which of the following enzymatic activities is NOT involved in DNA replication - Correct Ans: RNA-
dependent DNA polymerase
Which activity of DNA polymerase is responsible for its ability to proofread newly synthesized DNA -
Correct Ans: 3'>5' exonuclease which cleaves mismatched nucleotides
How many mutations would you expect to see in the human genome (6x10^9) if mismatches could not
be repaired? - Correct Ans: 6x10^9/10^4= 600,000 mutations
What would the consequences be of having DNA polymerase with out 5' -> 3' exonuclease activity? -
Correct Ans: the RNA primer will stay
What is the correct order of enzyme action during DNA replication? - Correct Ans:
helices/topoisomerase activity, priming, DNA polymerization/proofreading, 5'-3' exonuclease
activity/DNA polymerization, ligation
Why is telomerase important? - Correct Ans: It is important for extension
, You isolate a mutant of this gene that encodes the following protein:
N-Met-Gln-Cys-Lys-Ser-C
What mutation can give you this mutant protein - Correct Ans: Deletion of a C
Which of the following statements are FALSE? - Correct Ans: the Trp Operon is under positive control
*LAC has both positive and negative regulation* - Correct Ans:
Trp is negative controlled - Correct Ans:
Under which of the following conditions will E. coli make large amounts of B- galactosidase? - Correct
Ans: I+O+Z+, glucose absent, lactose present
I-OcZ+, glucose absent, lactose absent
Under what condition will E. coli make the least amount of B-galactosidase? - Correct Ans: IsO+Z+,
glucose absent, lactose present
For the lac operon gene regulation system, which of the following is false? - Correct Ans: in the
presence of low levels of glucose and lactose, even with mutation happening on the operator (operator
cannot bind to repressor), there are still no transcription of lac genes
The expression of a gene can be increase by? - Correct Ans: knocking out its repressor
In the Trp operon of E. coli, the Trytophan repressor protein, Trp R, will bind to the operator to prevent
transcription only in the presence of tryptophan. What is tryptophan an example of? - Correct Ans: Co-
repressor
Which of the following is required for transcription - Correct Ans: RNA polymerase
Which of the following nucleosomes modifications will lead to closed promoters - Correct Ans: De-
acetylation
Exam Questions
and Complete
Answers Graded
A+
Denning [Date] [Course title]
,What type of bonds are formed between complementary DNA bases? - Correct Ans: Hydrogen Bonds
Which of the following forms the backbone of a polynucleotide chain? - Correct Ans: alternating sugar
and phosphate groups
Guanine and adenine are purines found in DNA - Correct Ans: true
What fraction of the nucleotides in a doubles-stranded DNA molecule are cytosine and thymine? -
Correct Ans: 50%
What is one difference between DNA replication in bacteria versus eukaryotes? - Correct Ans:
Eukaryotic chromosomes have many origins of replication, while bacteria have only one origin of
replication
What is the maximum rate between DNA replication in E. coli - Correct Ans: 1000 nucleotides
During DNA replication in E. coli, what is the role of DnaA? - Correct Ans: DnaA bends DNA, hydrolyzing
the hydrogen bonds in the 13-mer region of otic and creating an open complex
Which of the following statements about DNA replication is true? - Correct Ans: Single-strand binding
proteins stabilize the open conformation of the unwound DNA
Which of the following reagents is not required for the polymerase chain reaction? - Correct Ans:
Dideoxynucleotide triphosphate
Which of the following would you find in a Sanger sequencing reaction but not in a polymerase chain
reaction? - Correct Ans: ddNTPs
Which of the following statements about ddNTPs is true? - Correct Ans: they have a hydrogen at the 3'
carbon of the sugar
,The principles of complementary base pairing and antiparallel polarity of nucleic acid strands is a duplex
are universal for the formation of nucleic acid duplexes. What is the chemical basis for this university? -
Correct Ans:
You wish to create a mutation in which you prevent access of RNA polymerase to the gene. Which
region of a gene would you target? - Correct Ans: promoter sequence
Which region(s) of a gene are not found within the mRNA transcript? - Correct Ans: promoter region
Which of the following statements regarding Nucleotide Excision repair (NER) and Base Excision Repair
(BER) is true? - Correct Ans: both NER and BER involve the removal of one or more damaged bases by a
nuclease
How large is an origin of replication of E. coli? - Correct Ans: 245 base pairs
Which of the following enzymatic activities is NOT involved in DNA replication - Correct Ans: RNA-
dependent DNA polymerase
Which activity of DNA polymerase is responsible for its ability to proofread newly synthesized DNA -
Correct Ans: 3'>5' exonuclease which cleaves mismatched nucleotides
How many mutations would you expect to see in the human genome (6x10^9) if mismatches could not
be repaired? - Correct Ans: 6x10^9/10^4= 600,000 mutations
What would the consequences be of having DNA polymerase with out 5' -> 3' exonuclease activity? -
Correct Ans: the RNA primer will stay
What is the correct order of enzyme action during DNA replication? - Correct Ans:
helices/topoisomerase activity, priming, DNA polymerization/proofreading, 5'-3' exonuclease
activity/DNA polymerization, ligation
Why is telomerase important? - Correct Ans: It is important for extension
, You isolate a mutant of this gene that encodes the following protein:
N-Met-Gln-Cys-Lys-Ser-C
What mutation can give you this mutant protein - Correct Ans: Deletion of a C
Which of the following statements are FALSE? - Correct Ans: the Trp Operon is under positive control
*LAC has both positive and negative regulation* - Correct Ans:
Trp is negative controlled - Correct Ans:
Under which of the following conditions will E. coli make large amounts of B- galactosidase? - Correct
Ans: I+O+Z+, glucose absent, lactose present
I-OcZ+, glucose absent, lactose absent
Under what condition will E. coli make the least amount of B-galactosidase? - Correct Ans: IsO+Z+,
glucose absent, lactose present
For the lac operon gene regulation system, which of the following is false? - Correct Ans: in the
presence of low levels of glucose and lactose, even with mutation happening on the operator (operator
cannot bind to repressor), there are still no transcription of lac genes
The expression of a gene can be increase by? - Correct Ans: knocking out its repressor
In the Trp operon of E. coli, the Trytophan repressor protein, Trp R, will bind to the operator to prevent
transcription only in the presence of tryptophan. What is tryptophan an example of? - Correct Ans: Co-
repressor
Which of the following is required for transcription - Correct Ans: RNA polymerase
Which of the following nucleosomes modifications will lead to closed promoters - Correct Ans: De-
acetylation
