BCHM 307 Exam 2 Questions and Answers Fully Solved Latest Update 2025-2026
An E. Coli has ___ replication fork(s) on its single chromosome; humans have ___ replication
fork(s) on each chromosome.
a. 2, 2
b. 2, many
c. 1, 1
d. many, many
e. 1, 2 - Answers b. 2, many
If the smallest human chromosome is 4.6 x 10^7 base pairs in length, which of the following is
the best estimate of the number of Okazaki fragments resulting from its replication?
a. 300,000
b. 30
c. 30,000
d. 3,000
e. 300 - Answers a. 300,000
Which of the following is correctly pairs with its function?
a. DNA ligase- joins the discontinuous segments on the lagging strand
b. RNase H- removal of RNA primer
c. Primase- production of an RNA primer for DNA polymerase
d. Helicase- creates single strand DNA
e. All of the above - Answers e. All of the above
Without telomeres, what would happen to the ends of eukaryotic chromosomes during
replication?
a. They would be replicated just like the rest of the chromosome
b. They would be shortened
c. They would be lengthened
d. They would be mutated - Answers b. They would be shortened
,In the nucleus, DNA is wrapped around ___ to form ___.
a. Polyribose, euchromatin
b. Histones, nucleosomes
c. Ribosomes, heterochromatin
d. Polyarginine, 30-nm fibers - Answers b. Histones, nucleosomes
An antibiotic that interferes with bacterial topoisomerase activity is ___ which specifically
inhibits ___.
a. Camptothecin, type II topoisomerase
b. Novobiocin, ATPase
c. Doxorubicin, type IA topoisomerase
d. Ciprofloxacin, DNA gyrase - Answers d. Ciprofloxacin, DNA gyrase
What does a reverse transcriptase do?
a. Replicated DNA in a 3' to 5' fashion
b. Replicates RNA in a 5' to 3' fashion
c. Replicated RNA in a 3' to 5' fashion
d. Converts a DNA genome into an RNA genome
e. Converts an RNA genome into a DNA genome - Answers e. Converts an RNA genome into a
DNA genome
Which of the following mutations would cause a bulge in the DNA backbone?
a. Point mutation
b. Transition mutation
c. Transversion mutation
d. Frameshift mutation
e. All of the above - Answers c. Transversion mutation
Which of the following best describes a new strand of DNA relative to the template strand used
to synthesize it?
a. An exact copy of the template but with the 3' to 5' ends reversed
, b. An exact duplicate of the template
c. A negative copy of the template
d. A palindromic copy of the template - Answers c. A negative copy of the template
In most organisms, replication proceeds in a ___ manner from the ___.
a. Bidirectional, replication origin
b. Bidirectional, lagging strand
c. Unidirectional, chromosome ends
d. Bidirectional, theta site - Answers a. Bidirectional, replication origin
Which of the following is a potential modification to DNA that can result in mutation n or
interfere with replication or transcription?
a. Formation of thymine dimers by reaction with UV light
b. Oxidation of guanine to 8-oxoguanine
c. Reaction with hydroxyl radicals causing DNA strand breaks
d. Deamination of cytosine to uracil
e. All of the above - Answers e. All of the above
Which DNA strand is replicated exclusively in a discontinuous fashion?
a. Leading strand
b. Forward strand
c. Reverse strand
d. The strand read in 5' to 3' direction
e. Lagging strand - Answers e. Lagging strand
Which tumor suppressor gene is found to be mutated in at least half of all human tumors?
a. p53
b. BRCA1
c. BRCA2
d. Retinoblastoma - Answers a. p53
An E. Coli has ___ replication fork(s) on its single chromosome; humans have ___ replication
fork(s) on each chromosome.
a. 2, 2
b. 2, many
c. 1, 1
d. many, many
e. 1, 2 - Answers b. 2, many
If the smallest human chromosome is 4.6 x 10^7 base pairs in length, which of the following is
the best estimate of the number of Okazaki fragments resulting from its replication?
a. 300,000
b. 30
c. 30,000
d. 3,000
e. 300 - Answers a. 300,000
Which of the following is correctly pairs with its function?
a. DNA ligase- joins the discontinuous segments on the lagging strand
b. RNase H- removal of RNA primer
c. Primase- production of an RNA primer for DNA polymerase
d. Helicase- creates single strand DNA
e. All of the above - Answers e. All of the above
Without telomeres, what would happen to the ends of eukaryotic chromosomes during
replication?
a. They would be replicated just like the rest of the chromosome
b. They would be shortened
c. They would be lengthened
d. They would be mutated - Answers b. They would be shortened
,In the nucleus, DNA is wrapped around ___ to form ___.
a. Polyribose, euchromatin
b. Histones, nucleosomes
c. Ribosomes, heterochromatin
d. Polyarginine, 30-nm fibers - Answers b. Histones, nucleosomes
An antibiotic that interferes with bacterial topoisomerase activity is ___ which specifically
inhibits ___.
a. Camptothecin, type II topoisomerase
b. Novobiocin, ATPase
c. Doxorubicin, type IA topoisomerase
d. Ciprofloxacin, DNA gyrase - Answers d. Ciprofloxacin, DNA gyrase
What does a reverse transcriptase do?
a. Replicated DNA in a 3' to 5' fashion
b. Replicates RNA in a 5' to 3' fashion
c. Replicated RNA in a 3' to 5' fashion
d. Converts a DNA genome into an RNA genome
e. Converts an RNA genome into a DNA genome - Answers e. Converts an RNA genome into a
DNA genome
Which of the following mutations would cause a bulge in the DNA backbone?
a. Point mutation
b. Transition mutation
c. Transversion mutation
d. Frameshift mutation
e. All of the above - Answers c. Transversion mutation
Which of the following best describes a new strand of DNA relative to the template strand used
to synthesize it?
a. An exact copy of the template but with the 3' to 5' ends reversed
, b. An exact duplicate of the template
c. A negative copy of the template
d. A palindromic copy of the template - Answers c. A negative copy of the template
In most organisms, replication proceeds in a ___ manner from the ___.
a. Bidirectional, replication origin
b. Bidirectional, lagging strand
c. Unidirectional, chromosome ends
d. Bidirectional, theta site - Answers a. Bidirectional, replication origin
Which of the following is a potential modification to DNA that can result in mutation n or
interfere with replication or transcription?
a. Formation of thymine dimers by reaction with UV light
b. Oxidation of guanine to 8-oxoguanine
c. Reaction with hydroxyl radicals causing DNA strand breaks
d. Deamination of cytosine to uracil
e. All of the above - Answers e. All of the above
Which DNA strand is replicated exclusively in a discontinuous fashion?
a. Leading strand
b. Forward strand
c. Reverse strand
d. The strand read in 5' to 3' direction
e. Lagging strand - Answers e. Lagging strand
Which tumor suppressor gene is found to be mutated in at least half of all human tumors?
a. p53
b. BRCA1
c. BRCA2
d. Retinoblastoma - Answers a. p53
