MMSC491 EXAM 1 2025 QUESTIONS AND
ANSWERS
In a DNA double helix each type of base forms a stable base pair with only one type of base.
When bases on an RNA strand are involved in base pairing, which bases can form stable base
pairs with more than one type of base? - ANS Guanine and Uracil
The sequence -GATCCAGGACCATGT- is part of a protein coding gene. Which of the following is
the sequence which would be found on the mRNA that would be produced from this sequence?
- ANS - CUAGGUCCUGGUACA -
In designing a hybridization assay that would accept only perfect base matching, which of the
following would be of optimal design? - ANS Use of a short single stranded oligonucleotide
probe and high hybridization conditions
Prolonged skin exposure to the sun in the absence of a UV protectant is likely to result in which
type of DNA damage? - ANS DNA base cross-linking
Regarding the structure of bases in nucleic acids, which, if any, of the following statements is
incorrect? - ANS Purines carry an amino group, unlike pyrimidines
Regarding the sugar residues in nucleic acids, which, if any, of the following statements is
incorrect? - ANS The internal sugar residues in a DNA strand normally have free hydroxyl
groups, unlike those in an RNA strand
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, Regarding DNA replication, which, if any, of the following statements is incorrect? - ANS DNA
replication is said to be semi-conservative because for each DNA helix only one strand serves as
a template for new DNA synthesis
Regarding DNA replication and DNA synthesis, which, if any, of the following statements is
incorrect? - ANS A DNA polymerase always requires a DNA template to synthesize a
complementary DNA
Which is the best definition of noncoding RNA? - ANS A functional RNA that is not translated
to make a protein
If we take the number of chromosomes in a haploid sperm cell or egg cell to be n and the total
content of genomic DNA to be C, what is the number of chromosomes and the total genomic
DNA content of a diploid G1 phase cell and in a diploid G2 phase cell from the same organism. -
ANS 2n chromosomes, DNA content of 2C in G1; 2n chromosomes, DNA content of 4C in G2
Regarding the cell cycle, which, if any, of the following statements is correct? - ANS The M
phase is the only phase in the cell cycle when chromosomes stained with chemical dyes are
visible under the light microscope
Which of the following statements is incorrect about DNA and RNA? - ANS The only
structural difference between DNA and RNA strands is that they have different sugars,
respectively deoxyribose and ribose
Which of the following statements is incorrect regarding base pairs? - ANS A-T base pairs are
stronger than G-C base pairs.
Which of the following statements is incorrect regarding evolution? - ANS Because
centromeres and telomeres are critically important for chromosome function their DNA has
been very highly conserved during evolution
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ANSWERS
In a DNA double helix each type of base forms a stable base pair with only one type of base.
When bases on an RNA strand are involved in base pairing, which bases can form stable base
pairs with more than one type of base? - ANS Guanine and Uracil
The sequence -GATCCAGGACCATGT- is part of a protein coding gene. Which of the following is
the sequence which would be found on the mRNA that would be produced from this sequence?
- ANS - CUAGGUCCUGGUACA -
In designing a hybridization assay that would accept only perfect base matching, which of the
following would be of optimal design? - ANS Use of a short single stranded oligonucleotide
probe and high hybridization conditions
Prolonged skin exposure to the sun in the absence of a UV protectant is likely to result in which
type of DNA damage? - ANS DNA base cross-linking
Regarding the structure of bases in nucleic acids, which, if any, of the following statements is
incorrect? - ANS Purines carry an amino group, unlike pyrimidines
Regarding the sugar residues in nucleic acids, which, if any, of the following statements is
incorrect? - ANS The internal sugar residues in a DNA strand normally have free hydroxyl
groups, unlike those in an RNA strand
1 @COPYRIGHT THEBRIGHT 2025/2026
, Regarding DNA replication, which, if any, of the following statements is incorrect? - ANS DNA
replication is said to be semi-conservative because for each DNA helix only one strand serves as
a template for new DNA synthesis
Regarding DNA replication and DNA synthesis, which, if any, of the following statements is
incorrect? - ANS A DNA polymerase always requires a DNA template to synthesize a
complementary DNA
Which is the best definition of noncoding RNA? - ANS A functional RNA that is not translated
to make a protein
If we take the number of chromosomes in a haploid sperm cell or egg cell to be n and the total
content of genomic DNA to be C, what is the number of chromosomes and the total genomic
DNA content of a diploid G1 phase cell and in a diploid G2 phase cell from the same organism. -
ANS 2n chromosomes, DNA content of 2C in G1; 2n chromosomes, DNA content of 4C in G2
Regarding the cell cycle, which, if any, of the following statements is correct? - ANS The M
phase is the only phase in the cell cycle when chromosomes stained with chemical dyes are
visible under the light microscope
Which of the following statements is incorrect about DNA and RNA? - ANS The only
structural difference between DNA and RNA strands is that they have different sugars,
respectively deoxyribose and ribose
Which of the following statements is incorrect regarding base pairs? - ANS A-T base pairs are
stronger than G-C base pairs.
Which of the following statements is incorrect regarding evolution? - ANS Because
centromeres and telomeres are critically important for chromosome function their DNA has
been very highly conserved during evolution
2 @COPYRIGHT THEBRIGHT 2025/2026
