BIO 344/BIO344-LATEST 2024/2025-(GRADED A+) ACCURATELY
SOLVED
Write legibly. Instructor and my grader should be able to read your answers. If we can’t read, there will be no
point. Write in pen and you have 75 min for the exam. Make sure you have all 4 pages (Total 120 pt).
QUESTIONS 1-15: MULTIPLE CHOICE (2 pt each, total 30 pt) Please write down your answer in the TABLE
provided.
1. What is the difference between a ribonucleotide and a deoxyribonucleotide?
A. ribonucleotides contain a phosphate group.
B. ribonucleotides have a hydroxyl group on the 2′ carbon of their sugar subunit.
C. ribonucleotides contain a sugar with five carbon atoms.
D. ribonucleotides have a hydrogen atom on the 1′ carbon of their sugar subunit.
2. A nucleotide is made up of which of the following subunits?
A. a 5-carbon sugar, a phosphate group, and a nitrogenous base
B. a 5-carbon sugar, a sulfate group, and a nitrogenous base
C. a 5-carbon sugar and a nitrogenous base
D. a 5-carbon sugar, an amino group, and an “R-group”
3. What forms the “backbone” of a nucleic acid?
A. a chain of sugar and phosphate groups, linked through phosphodiester bonds
B. purine and pyrimidine pairs, hydrogen-bonded to each other
C. a chain of amino and carboxyl groups, linked via peptide bonds
D. a double helix of antiparallel strands
4. By convention, the sequence of bases in a nucleic acid is always written in which direction?
A. amino to carboxyl B. carboxyl to amino
C. 3′ to 5′ D. 5′ to 3′
5. One DNA molecule varies from another by the
A. composition of the sugar-phosphate backbone
B. spacing of the major and minor grooves
C. way in which the bases are attached to the sugars
D. sequence of nitrogenous bases
6. The term ribozyme describes what property of RNA molecules?
A. they are single-stranded B. they can be catalytic
C. their shape D. the formation of hairpin loops
7. Which statement is true?
A. All proteins are enzymes.
B. All proteins are enzymes, and some RNA molecules also are catalytic.
C. All enzymes are proteins.
D. Most enzymes are proteins, but some RNA molecules also are catalytic.
8. A retrovirus, such as HIV-1,
A. uses non-coding RNAs to package its genome into a capsid
B. stores its genome as an RNA sequence
C. uses host cell ribozymes to process its genome
D. converts its DNA genome to an RNA once inside the host cell
9. Amino acids are joined by a condensation reaction to form a polypeptide chain with a
backbone and side chain.
A. variable, common B. variable, variable
C. common, variable D. common, common
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, 10. The primary structure of a protein is
A. the sequence of a chain of amino acids joined together by phosphodiester bonds.
B. the sequence of a chain of amino acids joined together by peptide bonds.
C. nearby amino acids in a chain joined together by hydrogen bonds.
D. the three-dimensional folding of amino acids in a chain.
11. The C-terminus of a protein corresponds to
A. the R-group of the first amino acid B. the R-group of the last amino acid
C. the amino group of the first amino acid D. the carboxyl group of the last amino acid
12. You determine that a protein has an attached polyubiquitin chain. It is likely that this protein will be
A. targeted to the lysosome for degradation. B. targeted to the 26S proteosome.
C. included in insoluble toxic deposits known as amyloids fibers. D. degraded by E1, E2, and E3 enzymes.
13. Heterochromatin is
A. condensed, transcriptionally active chromatin. B. condensed, transcriptionally silent chromatin.
C. decondensed, transcriptionally active chromatin. D. decondensed, transcriptionally silent chromatin.
14. Which of the following properties do you predict to be most critical to histone association with DNA?
A. Histones are small proteins. B. Histones are positively charged.
C. Histones are highly conserved. D. There are at least five different histone proteins in every eukaryotic cell.
15. RNA is involved in both DNA replication and translation. A. True B. False
QUESTIONS 16-23: TERM/STRUCTURE (total 16 pt)
16-19. In the Hershey-Chase experiment, phage proteins were labeled with 35-sulfer (35S). What are the two
sulfer containing amino acids? Draw matching amino acid structures. (2 pt each, total 8pt)
20-23. As you see from the example below, histone proteins can be post-translationally modified. Two amino
acids are often methylated. What are these two basic amino acids (full names)? Draw structure of each amino
acid. (2 pt each, total 8pt)
QUESTIONS 24-32: SHORT DESCRIPTION (total 42 pt)
24. What is the main goal of the ENCODE project? (2pt)
To fully describe the list of functional (cis-regulatory) elements that make up the human genome
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SOLVED
Write legibly. Instructor and my grader should be able to read your answers. If we can’t read, there will be no
point. Write in pen and you have 75 min for the exam. Make sure you have all 4 pages (Total 120 pt).
QUESTIONS 1-15: MULTIPLE CHOICE (2 pt each, total 30 pt) Please write down your answer in the TABLE
provided.
1. What is the difference between a ribonucleotide and a deoxyribonucleotide?
A. ribonucleotides contain a phosphate group.
B. ribonucleotides have a hydroxyl group on the 2′ carbon of their sugar subunit.
C. ribonucleotides contain a sugar with five carbon atoms.
D. ribonucleotides have a hydrogen atom on the 1′ carbon of their sugar subunit.
2. A nucleotide is made up of which of the following subunits?
A. a 5-carbon sugar, a phosphate group, and a nitrogenous base
B. a 5-carbon sugar, a sulfate group, and a nitrogenous base
C. a 5-carbon sugar and a nitrogenous base
D. a 5-carbon sugar, an amino group, and an “R-group”
3. What forms the “backbone” of a nucleic acid?
A. a chain of sugar and phosphate groups, linked through phosphodiester bonds
B. purine and pyrimidine pairs, hydrogen-bonded to each other
C. a chain of amino and carboxyl groups, linked via peptide bonds
D. a double helix of antiparallel strands
4. By convention, the sequence of bases in a nucleic acid is always written in which direction?
A. amino to carboxyl B. carboxyl to amino
C. 3′ to 5′ D. 5′ to 3′
5. One DNA molecule varies from another by the
A. composition of the sugar-phosphate backbone
B. spacing of the major and minor grooves
C. way in which the bases are attached to the sugars
D. sequence of nitrogenous bases
6. The term ribozyme describes what property of RNA molecules?
A. they are single-stranded B. they can be catalytic
C. their shape D. the formation of hairpin loops
7. Which statement is true?
A. All proteins are enzymes.
B. All proteins are enzymes, and some RNA molecules also are catalytic.
C. All enzymes are proteins.
D. Most enzymes are proteins, but some RNA molecules also are catalytic.
8. A retrovirus, such as HIV-1,
A. uses non-coding RNAs to package its genome into a capsid
B. stores its genome as an RNA sequence
C. uses host cell ribozymes to process its genome
D. converts its DNA genome to an RNA once inside the host cell
9. Amino acids are joined by a condensation reaction to form a polypeptide chain with a
backbone and side chain.
A. variable, common B. variable, variable
C. common, variable D. common, common
00 1
, 10. The primary structure of a protein is
A. the sequence of a chain of amino acids joined together by phosphodiester bonds.
B. the sequence of a chain of amino acids joined together by peptide bonds.
C. nearby amino acids in a chain joined together by hydrogen bonds.
D. the three-dimensional folding of amino acids in a chain.
11. The C-terminus of a protein corresponds to
A. the R-group of the first amino acid B. the R-group of the last amino acid
C. the amino group of the first amino acid D. the carboxyl group of the last amino acid
12. You determine that a protein has an attached polyubiquitin chain. It is likely that this protein will be
A. targeted to the lysosome for degradation. B. targeted to the 26S proteosome.
C. included in insoluble toxic deposits known as amyloids fibers. D. degraded by E1, E2, and E3 enzymes.
13. Heterochromatin is
A. condensed, transcriptionally active chromatin. B. condensed, transcriptionally silent chromatin.
C. decondensed, transcriptionally active chromatin. D. decondensed, transcriptionally silent chromatin.
14. Which of the following properties do you predict to be most critical to histone association with DNA?
A. Histones are small proteins. B. Histones are positively charged.
C. Histones are highly conserved. D. There are at least five different histone proteins in every eukaryotic cell.
15. RNA is involved in both DNA replication and translation. A. True B. False
QUESTIONS 16-23: TERM/STRUCTURE (total 16 pt)
16-19. In the Hershey-Chase experiment, phage proteins were labeled with 35-sulfer (35S). What are the two
sulfer containing amino acids? Draw matching amino acid structures. (2 pt each, total 8pt)
20-23. As you see from the example below, histone proteins can be post-translationally modified. Two amino
acids are often methylated. What are these two basic amino acids (full names)? Draw structure of each amino
acid. (2 pt each, total 8pt)
QUESTIONS 24-32: SHORT DESCRIPTION (total 42 pt)
24. What is the main goal of the ENCODE project? (2pt)
To fully describe the list of functional (cis-regulatory) elements that make up the human genome
00 2
