BIOL 2053 Exam #3 (Grade 1) for Principles of
Genetics 2025 Louisiana State University
Exam #3 (Grade 1) for Principles of Genetics, Fall Term 2025, Section 5-10.
Bubble in your name and student identification number on SIDE TWO of the
scantron. Also, you need to mark in the grade section whether your exam is Grade 1
or 2. The correct answer for each question will be awarded 3 points (3 x 33 = 99)
and one extra point will be added to make 100 point. Keep this exam booklet and
bring it to your next discussion session, when the exam will be reviewed.
(Q1-5) The following chemical constituents are found as structural components of
DNA and RNA.
a. phosphodiester b. phosphate c. adenine d. guanine
e. cytosine f. thymine g. uracil h. ribose
i. deoxyribose
1. Which chemical constituents are found in dGTP?
A. a, d, h
B. b, d, h
C. a, d, i
D. b, d, i
E. a, c, i
2. Which chemical constituents are found in CTP?
A. a, e, h,
B. b, e, h
C. a, e, i
D. b, e, i
E. b, g, i
3. Which chemical constituents are unique to RNA?
A. a, f
B. f, h
C. f, i
D. g, h
E. g, i
4. Which chemical constituents make up a nucleotide?
A. a, b, h
B. a, b, i
C. b, c, i
D. b, c
E. c, i
5. Which chemical constituents are purine bases?
A. c, d
B. c, e
C. d, e
D. e, f
E. f, g
,(Q6-7) We have the following set of single-stranded nucleic acids, which have been isolated
from human cells.
a 5'-UUACGAGCUUAAGCCU-3'
b 5'-AGGCTTAAGCTCGTAA-3'
c 5'-AGGCUUAAGCUCGUAA-3'
d 5'-TTACGAGCTTAAGCCT-3'
e 5'-UUACGAGCTTAAGCCT-3'
6. Which pair will make a complete double-stranded DNA based on the Watson-
Crick base-pairing rule?
A. a, b
B. c, d
C. d, e
D. b, d
E. c, e
7. Which one is most likely an Okazaki fragment with DNA and RNA?
A. a
B. b
C. c
D. d
E. e
(Q8-10) The following double-stranded DNA was found in the middle of DNA replication.
5’-GGGGTTGGGGATTTAGCTCAGTGGTAGAGCGCTTGCCT-3’
3’-CCCCAA-------------------------------GTCACCATCTCGCGAACGGA-5’
8. In the above DNA sequence, what sequence will fit in the missing portion?
A. 3’-AGCTAAATCCCC-5’
B. 5’-CCCCTAAATCGA-3’
C. 5’-AGCTAAATCCCC-3’
D. 3’-CCCCUAAAUCGA-5’
E. 5’-AGCUAAAUCCCC-3’
9. If you allow one round of replication of the above DNA, how many times you will
come across the following short DNA sequence?
(5’-AGCTC-3’)
A. 1
B. 2
C. 4
D. 8
E. 0
,10. Let's assume that the bold-typed region is a primer itself during DNA replication,
what will be the correct sequence of that primer?
A. 3’-ACTGAGCT-5’
B. 5’-ACTGAGCT-3’
C. 5’-ACUGAGCU-3’
D. 3’-AGCTCAGT-5’
E. 5’-AGCUCAGU-3’
11. Which of the followings will requires only DNA Pol III for completing DNA
replication?
A. 5'-AAGGCCTAACC-3'
5'-CCTTAAGTTGG-3'
B. 5'-AAGGCCTAACC-3'
3'-GGAUUGG-5'
C. 5'-CCTAACC-3'
3'-TTCCGGATTGG-5'
D. 5'-CCTAACC-3'
3'-TTCCGGA-5'
E. 5'-TTCCGGA-3'
3'-CCTAACC-5'
(Q12-17) A group of scientists obtained a mouth-swab sample from a potential
COVID-19 patient. Subsequently, they isolated a set of DNA and mRNA, the
sequences of which are shown below. They suspected that the mRNA might be
derived from this DNA based on the sequence similarity. Since the mouth-swab
sample could potentially have cells from human, bacteria and virus, they are not
certain of the source of this DNA and RNA. Answer the questions based on the
information learned from the lecture.
DNA
5’-GAGCTCAGTGGTACAATGTTCAGTAACCTTGACTGGCTGGTTCTTATGACTGG-3’
3’-CTCGAGTCACCATGTTACAAGTCATTGGAACTGACCGACCAAGAATACTGACC-5’
RNA
5'-mGpppCAAUGUUCAGCUGGUUCUUAUGAAAAAAAAAAAAAAAAAAA-3'
(m indicate methylation; ppp indicates 5'-5' phosphodiester bond in RNA sequence)
12. Based on the structure and sequence of this mRNA, which organism is the source
of this mRNA and DNA?
A. Human
B. Bacteria
C. Virus
D. None of the above
, E. We cannot tell.
13. Let's assume that this mRNA has been indeed derived from this DNA with
splicing. Then, which RNA polymerase has been used?
A. virus RNA Pol
B. bacteria RNA Pol
C. human RNA Pol I
D. human RNA Pol II
E. human RNA Pol III
14. In which direction does RNA polymerase move (or transcribe) on the DNA to make
this mRNA, and which strand does RNA polymerase use as the template for this
transcription?
A. left-to-right, top
B. left-to-right, bottom
C. right-to-left, top
D. right-to-left, bottom
E. none of the above
15. Also, the sequence of this RNA seems to match with the sequence of DNA but
with an interruption, suggesting the presence of a potential Intron. Then, which is
this removed RNA sequence by splicing?
A. 5'-TAACCTTGACTGG-3'
B. 3'-TAACCTTGACTGG-5'
C. 5'-UAACCUUGACUGG-3
D. 3'-UAACCUUGACUGG-5'
E. none of the above
16. If this mRNA can code for a small peptide, how long is this peptide?
(AUG - START codon and UGA - STOP codon)
A. 5 amino acid long
B. 6 amino acid long
C. 7 amino acid long
D. 8 amino acid long
E. 9 amino acid long
17. Which is the correct anticodon for 2nd amino acid?
A. 5'-UAC-3'
B. 3'-UAC-5'
C. 5'-GUU-3
D. 3'-GUU-5'
E. none of the above.
Genetics 2025 Louisiana State University
Exam #3 (Grade 1) for Principles of Genetics, Fall Term 2025, Section 5-10.
Bubble in your name and student identification number on SIDE TWO of the
scantron. Also, you need to mark in the grade section whether your exam is Grade 1
or 2. The correct answer for each question will be awarded 3 points (3 x 33 = 99)
and one extra point will be added to make 100 point. Keep this exam booklet and
bring it to your next discussion session, when the exam will be reviewed.
(Q1-5) The following chemical constituents are found as structural components of
DNA and RNA.
a. phosphodiester b. phosphate c. adenine d. guanine
e. cytosine f. thymine g. uracil h. ribose
i. deoxyribose
1. Which chemical constituents are found in dGTP?
A. a, d, h
B. b, d, h
C. a, d, i
D. b, d, i
E. a, c, i
2. Which chemical constituents are found in CTP?
A. a, e, h,
B. b, e, h
C. a, e, i
D. b, e, i
E. b, g, i
3. Which chemical constituents are unique to RNA?
A. a, f
B. f, h
C. f, i
D. g, h
E. g, i
4. Which chemical constituents make up a nucleotide?
A. a, b, h
B. a, b, i
C. b, c, i
D. b, c
E. c, i
5. Which chemical constituents are purine bases?
A. c, d
B. c, e
C. d, e
D. e, f
E. f, g
,(Q6-7) We have the following set of single-stranded nucleic acids, which have been isolated
from human cells.
a 5'-UUACGAGCUUAAGCCU-3'
b 5'-AGGCTTAAGCTCGTAA-3'
c 5'-AGGCUUAAGCUCGUAA-3'
d 5'-TTACGAGCTTAAGCCT-3'
e 5'-UUACGAGCTTAAGCCT-3'
6. Which pair will make a complete double-stranded DNA based on the Watson-
Crick base-pairing rule?
A. a, b
B. c, d
C. d, e
D. b, d
E. c, e
7. Which one is most likely an Okazaki fragment with DNA and RNA?
A. a
B. b
C. c
D. d
E. e
(Q8-10) The following double-stranded DNA was found in the middle of DNA replication.
5’-GGGGTTGGGGATTTAGCTCAGTGGTAGAGCGCTTGCCT-3’
3’-CCCCAA-------------------------------GTCACCATCTCGCGAACGGA-5’
8. In the above DNA sequence, what sequence will fit in the missing portion?
A. 3’-AGCTAAATCCCC-5’
B. 5’-CCCCTAAATCGA-3’
C. 5’-AGCTAAATCCCC-3’
D. 3’-CCCCUAAAUCGA-5’
E. 5’-AGCUAAAUCCCC-3’
9. If you allow one round of replication of the above DNA, how many times you will
come across the following short DNA sequence?
(5’-AGCTC-3’)
A. 1
B. 2
C. 4
D. 8
E. 0
,10. Let's assume that the bold-typed region is a primer itself during DNA replication,
what will be the correct sequence of that primer?
A. 3’-ACTGAGCT-5’
B. 5’-ACTGAGCT-3’
C. 5’-ACUGAGCU-3’
D. 3’-AGCTCAGT-5’
E. 5’-AGCUCAGU-3’
11. Which of the followings will requires only DNA Pol III for completing DNA
replication?
A. 5'-AAGGCCTAACC-3'
5'-CCTTAAGTTGG-3'
B. 5'-AAGGCCTAACC-3'
3'-GGAUUGG-5'
C. 5'-CCTAACC-3'
3'-TTCCGGATTGG-5'
D. 5'-CCTAACC-3'
3'-TTCCGGA-5'
E. 5'-TTCCGGA-3'
3'-CCTAACC-5'
(Q12-17) A group of scientists obtained a mouth-swab sample from a potential
COVID-19 patient. Subsequently, they isolated a set of DNA and mRNA, the
sequences of which are shown below. They suspected that the mRNA might be
derived from this DNA based on the sequence similarity. Since the mouth-swab
sample could potentially have cells from human, bacteria and virus, they are not
certain of the source of this DNA and RNA. Answer the questions based on the
information learned from the lecture.
DNA
5’-GAGCTCAGTGGTACAATGTTCAGTAACCTTGACTGGCTGGTTCTTATGACTGG-3’
3’-CTCGAGTCACCATGTTACAAGTCATTGGAACTGACCGACCAAGAATACTGACC-5’
RNA
5'-mGpppCAAUGUUCAGCUGGUUCUUAUGAAAAAAAAAAAAAAAAAAA-3'
(m indicate methylation; ppp indicates 5'-5' phosphodiester bond in RNA sequence)
12. Based on the structure and sequence of this mRNA, which organism is the source
of this mRNA and DNA?
A. Human
B. Bacteria
C. Virus
D. None of the above
, E. We cannot tell.
13. Let's assume that this mRNA has been indeed derived from this DNA with
splicing. Then, which RNA polymerase has been used?
A. virus RNA Pol
B. bacteria RNA Pol
C. human RNA Pol I
D. human RNA Pol II
E. human RNA Pol III
14. In which direction does RNA polymerase move (or transcribe) on the DNA to make
this mRNA, and which strand does RNA polymerase use as the template for this
transcription?
A. left-to-right, top
B. left-to-right, bottom
C. right-to-left, top
D. right-to-left, bottom
E. none of the above
15. Also, the sequence of this RNA seems to match with the sequence of DNA but
with an interruption, suggesting the presence of a potential Intron. Then, which is
this removed RNA sequence by splicing?
A. 5'-TAACCTTGACTGG-3'
B. 3'-TAACCTTGACTGG-5'
C. 5'-UAACCUUGACUGG-3
D. 3'-UAACCUUGACUGG-5'
E. none of the above
16. If this mRNA can code for a small peptide, how long is this peptide?
(AUG - START codon and UGA - STOP codon)
A. 5 amino acid long
B. 6 amino acid long
C. 7 amino acid long
D. 8 amino acid long
E. 9 amino acid long
17. Which is the correct anticodon for 2nd amino acid?
A. 5'-UAC-3'
B. 3'-UAC-5'
C. 5'-GUU-3
D. 3'-GUU-5'
E. none of the above.
