MMSC490 LATEST 2026 STUDY GUIDE QUESTIONS AND
SOLUTIONS GUARANTEE A+
✔✔Point mutations in DNA result from
a. incorporation of incorrect bases during replication.
b. changes as a result of chemical exposure.
c. changes as a result of radiation exposure.
d. All of the above - ✔✔d. All of the above
✔✔The most common cause of skin cancer is damage to DNA by
a. infrared light.
b. ultraviolet light.
c. γ radiation.
d. β particle radiation. - ✔✔b. ultraviolet light.
✔✔Pyrimidine dimers
a. block DNA replication and transcription.
b. can be repaired by photoreactivation.
c. can be repaired by nucleotide-excision repair.
d. All of the above - ✔✔d. All of the above
✔✔Cultured cells from xeroderma pigmentosum patients were unable to carry out
a. DNA synthesis
b. synthesis of melanin.
c. nucleotide-excision repair.
d. base-excision repair. - ✔✔c. nucleotide-excision repair.
✔✔E. coli DNA polymerase V
a. is induced in response to high temperatures.
b. recognizes thymidine dimers and inserts nucleotides on the opposite strand.
c. has a low frequency of errors.
d. is activated during transcription. - ✔✔b. recognizes thymidine dimers and inserts
nucleotides on the opposite strand.
✔✔Site-specific recombination
a. occurs in randomly occurring DNA sequences.
b. is mediated by proteins that recognize specific DNA target sequences.
c. leads to programmed cell death.
d. is also referred to as homologous recombination. - ✔✔b. is mediated by proteins that
recognize specific DNA target sequences.
✔✔Site-specific recombination occurs commonly during
a. mitosis of somatic cells.
b. meiosis of germ cells.
, c. development of immune-system cells.
d. prokaryotic cell division. - ✔✔c. development of immune-system cells.
✔✔The DNA sequence to which an RNA polymerase binds to initiate transcription of a
gene is called a(n)
a. enhancer.
b. promoter.
c. polymerase-binding element.
d. origin of transcription. - ✔✔b. promoter.
✔✔The regions of the DNA where RNA polymerase binds can be identified by
a. restriction mapping.
b. PCR.
c. mutagenesis in the -35 and -10 promoter regions that inhibits transcription.
d. polymerase mapping. - ✔✔c. mutagenesis in the -35 and -10 promoter regions that
inhibits transcription.
✔✔Termination of transcription in E. coli is signaled by
a. formation of a stem-loop structure in the RNA.
b. binding of Rho protein to the end of the mRNA.
c. binding of a sigma (σ) factor to the end of the mRNA.
d. an inverted GC-rich sequence followed by seven A residues. - ✔✔d. an inverted GC-
rich sequence followed by seven A residues.
✔✔The pioneering studies of gene regulation in E. coli were conducted in the 1950s by
a. Miller and Urey.
b. Watson and Crick.
c. Jacob and Monod.
d. Lerner and Lowe. - ✔✔c. Jacob and Monod.
✔✔The lac operator consists of approximately 20 base pairs of DNA located
a. 80-100 base pairs upstream of the transcription initiation site.
b. 20-40 base pairs upstream of the transcription initiation site.
c. in a position overlapping the initiation site.
d. downstream of the transcription initiation site. - ✔✔c. in a position overlapping the
initiation site.
✔✔Catabolite repression in E. coli
a. inhibits the breakdown of glucose in the presence of lactose.
b. is reversed by cAMP binding to catabolite activator protein.
c. inhibits the lac operon unless lactose is present.
d. is a negative feedback system. - ✔✔b. is reversed by cAMP binding to catabolite
activator protein.
SOLUTIONS GUARANTEE A+
✔✔Point mutations in DNA result from
a. incorporation of incorrect bases during replication.
b. changes as a result of chemical exposure.
c. changes as a result of radiation exposure.
d. All of the above - ✔✔d. All of the above
✔✔The most common cause of skin cancer is damage to DNA by
a. infrared light.
b. ultraviolet light.
c. γ radiation.
d. β particle radiation. - ✔✔b. ultraviolet light.
✔✔Pyrimidine dimers
a. block DNA replication and transcription.
b. can be repaired by photoreactivation.
c. can be repaired by nucleotide-excision repair.
d. All of the above - ✔✔d. All of the above
✔✔Cultured cells from xeroderma pigmentosum patients were unable to carry out
a. DNA synthesis
b. synthesis of melanin.
c. nucleotide-excision repair.
d. base-excision repair. - ✔✔c. nucleotide-excision repair.
✔✔E. coli DNA polymerase V
a. is induced in response to high temperatures.
b. recognizes thymidine dimers and inserts nucleotides on the opposite strand.
c. has a low frequency of errors.
d. is activated during transcription. - ✔✔b. recognizes thymidine dimers and inserts
nucleotides on the opposite strand.
✔✔Site-specific recombination
a. occurs in randomly occurring DNA sequences.
b. is mediated by proteins that recognize specific DNA target sequences.
c. leads to programmed cell death.
d. is also referred to as homologous recombination. - ✔✔b. is mediated by proteins that
recognize specific DNA target sequences.
✔✔Site-specific recombination occurs commonly during
a. mitosis of somatic cells.
b. meiosis of germ cells.
, c. development of immune-system cells.
d. prokaryotic cell division. - ✔✔c. development of immune-system cells.
✔✔The DNA sequence to which an RNA polymerase binds to initiate transcription of a
gene is called a(n)
a. enhancer.
b. promoter.
c. polymerase-binding element.
d. origin of transcription. - ✔✔b. promoter.
✔✔The regions of the DNA where RNA polymerase binds can be identified by
a. restriction mapping.
b. PCR.
c. mutagenesis in the -35 and -10 promoter regions that inhibits transcription.
d. polymerase mapping. - ✔✔c. mutagenesis in the -35 and -10 promoter regions that
inhibits transcription.
✔✔Termination of transcription in E. coli is signaled by
a. formation of a stem-loop structure in the RNA.
b. binding of Rho protein to the end of the mRNA.
c. binding of a sigma (σ) factor to the end of the mRNA.
d. an inverted GC-rich sequence followed by seven A residues. - ✔✔d. an inverted GC-
rich sequence followed by seven A residues.
✔✔The pioneering studies of gene regulation in E. coli were conducted in the 1950s by
a. Miller and Urey.
b. Watson and Crick.
c. Jacob and Monod.
d. Lerner and Lowe. - ✔✔c. Jacob and Monod.
✔✔The lac operator consists of approximately 20 base pairs of DNA located
a. 80-100 base pairs upstream of the transcription initiation site.
b. 20-40 base pairs upstream of the transcription initiation site.
c. in a position overlapping the initiation site.
d. downstream of the transcription initiation site. - ✔✔c. in a position overlapping the
initiation site.
✔✔Catabolite repression in E. coli
a. inhibits the breakdown of glucose in the presence of lactose.
b. is reversed by cAMP binding to catabolite activator protein.
c. inhibits the lac operon unless lactose is present.
d. is a negative feedback system. - ✔✔b. is reversed by cAMP binding to catabolite
activator protein.
