Title: Exam 2
Course: BTEC-1100-301-302-303-F21 > Section: Module 2 - Molecular Biology

Q: Which of the following statements about DNA is FALSE?
- DNA is capable of forming many different sequences.
- DNA contains thymine instead of uracil.
- DNA is double-stranded rather than single-stranded.
- DNA is only found in eukaryotic cells.
- DNA contains the sugar deoxyribose.
A: DNA is only found in eukaryotic cells.

Q: The information carried by DNA is incorporated in a code specified by the:
- phosphodiester bonds of the DNA strand.
- number of separate strands of DNA.
- size of a particular chromosome.
- specific nucleotide sequence of the DNA molecule.
- number of bases in a DNA strand.
A: specific nucleotide sequence of the DNA molecule.

Q: The two molecules that alternate to form the backbone of a polynucleotide chain are:
- adenine and thymine.
- cytosine and guanine.
- sugar and phosphate.
- base and sugar.
- base and phosphate.
A: sugar and phosphate.

Q: In DNA, the genetic information:
- is contained in each strand.
- is contained in only one of the strands.
- is contained in both strands together.
- is contained in the differences between the 2 strands.
- None of the above.
A: None of the above.

Q: Two chains of DNA must run in ____________ direction(s) and must be ____________ if they are to bond with each other.
- the same; uncomplementary
- opposite; uncomplementary
- parallel; uncomplementary
- parallel; complementary
- antiparallel; complementary
A: antiparallel; complementary

Q: The portion of the molecule in box 5 of Figure 11-01 is:
- a hydrogen bond.
- a phosphate.
- a nucleotide.
- a pyrimidine.
- a protein.
A: a phosphate.

Q: In Figure 11-01, the portion of the molecule in box _________ is a pyrimidine.
- 1
- 3
- 4
- 1 and 3
- 3 and 4
A: 1

Q: The portion of the molecule in box 3 of Figure 11-01 is:
- a sugar.
- a protein.
- a pyrimidine.
- a purine.
- a nucleotide.
A: a purine.

Q: How is a single strand of DNA able to serve as a template for the synthesis of another strand?
- a - Nucleotides pair with those of the original strand to form a new strand.
- b - Hydrogen bonds holding the two strands together are easy to break, allowing one strand to be a template.
- c - A single strand of DNA is not able to serve as a template.
- d - One strand of DNA directs the synthesis of a new strand on its partner.
- e - Both A and B.
A: e - Both A and B.

Q: Which of the following best describes semiconservative replication?
- The translation of a DNA molecule into a complementary strand of RNA.
- A DNA molecule consists of one parental strand and one new strand.
- The number of DNA molecules is doubled with every other replication.
- The replication of DNA never takes place with 100% accuracy.
- The replication of DNA takes place at a defined period in the cell cycle.
A: A DNA molecule consists of one parental strand and one new strand.

Q: If DNA replication rejoined the 2 parental strands, it would be termed:
- dispersive.
- gradient.
- semiconservative.
- parental.
- conservative.
A: conservative.

Q: Why does DNA synthesis only proceed in the 5'to 3' direction?
- Because DNA polymerases can only add nucleotides to the 3' end of a polynucleotide strand.
- Because the 3' end of the polynucleotide molecule is more electronegative than the 5' end.
- Because that is the direction in which the two strands of DNA unzip.
- Because that is the only direction that the polymerase can be oriented.
- Because the chromosomes are always aligned in the 5' to 3' direction in the nucleus.
A: Because DNA polymerases can only add nucleotides to the 3' end of a polynucleotide strand.

Q: Which of the following adds new nucleotides to a growing DNA chain?
- DNA polymerase
- DNA helicase
- RNA primer
- primase
- RNA polymerase
A: DNA polymerase

Q: The correct designation for the DNA strand labeled C in Figure 11-02 is:
- the leading strand.
- 3'.
- Okazaki fragments.
- polymerase.
- None of the above.
A: None of the above.

Q: The segments labeled F in Figure 11-02 are responsible for:
- linking short DNA segments.
- synthesizing the leading strand.
- forming the replication fork.
- initiating DNA synthesis.
- unwinding the DNA double helix.
A: initiating DNA synthesis.

Q: The enzyme represented by the letter D in Figure 11-02 is responsible for:
- linking short DNA segments.
- synthesizing the leading strand.
- forming the replication fork.
- forming nucleosomes.
- unwinding the DNA double helix.
A: linking short DNA segments.

Q: The structures represented by the letter E in Figure 11-02 are called:
- leading fragments
- Okazaki fragments.
- replication forks.
- nucleosomes.
- DNA polymerases.
A: Okazaki fragments.

Q: One of the mRNA codons specifying the amino acid leucine is 5'-CUA-3'. Its corresponding anticodon is:
- 5'-GAT-3'.
- 3'-AUC-5'.
- 3'-GAU-5'.
- 3'-GAT-5'.
- 5'-GAU-3'.
A: 3'-GAU-5'.

Q: Which of the following is a characteristic of uracil?
- The ability to bond with adenine.
- The ability to bond with guanine.
- It is a purine.
- The ability to bond with cytosine.
- It contains two nitrogenous rings.
A: The ability to bond with adenine.

Q: RNA differs from DNA in all the following except:
- RNA is single stranded and DNA is double stranded.
- RNA is a larger molecule than DNA.
- RNA contains uracil and DNA contains thymine.
- RNA contains ribose and DNA contains deoxyribose.
- None of the above.
A: RNA is a larger molecule than DNA.

Q: RNA synthesis is also known as:
- elongation.
- reverse transcription.
- termination.
- translation.
- transcription.
A: transcription.

Q: All RNA except for _________ is made from DNA.
- tRNA
- mRNA
- rRNA
- snRNA
- None of the above.
A: None of the above.

Q: During protein synthesis, ribosomes:
- attach to the mRNA molecule and travel along its length.
- attach to the DNA molecule and travel along its length to produce an mRNA molecule.
- translate mRNA into tRNA.
- transcribe mRNA to tRNA.
- translate mRNA into DNA.
A: attach to the mRNA molecule and travel along its length.

Q: Why is only one strand of DNA transcribed into mRNA?
- Because mRNA is only required in small quantities.
- Because transcribing both DNA strands would produce different amino acid sequences.
- Because the other strand would produce the same amino acid sequence in reverse order.
- Because all genes are located on the same DNA strand, while the other strand acts as protection.
- Because the other strand is transcribed directly into amino acids.
A: Because transcribing both DNA strands would produce different amino acid sequences.

Q: Initiation of transcription requires:
- a promoter sequence.
- DNA polymerase.
- an RNA primer.
- a DNA primer.
- Okazaki fragments.
A: a promoter sequence.

Q: In Figure 12-02, the transcription process begins at the area labeled:
- A.
- D.
- E.
- G.
- None of the above.
A: E.

Q: The component labeled B in Figure 12-02 is:
- DNase.
- DNA polymerase.
- RNA primase.
- RNA polymerase.
- reverse transcriptase.
A: RNA polymerase.

Q: The transcript in Figure 12-02 is labeled:
- D.
- C.
- G.
- H.
- A.
A: D.

Q: The process illustrated in Figure 12-02 is:
- DNA synthesis.
- translation.
- transcription.
- a frame shift mutation.
- protein synthesis.
A: transcription.

Q: Aminoacyl-tRNA synthetases ________ link ________ to their respective tRNA molecules.
- ionically; mRNAs
- loosely; mRNAs
- terminally; codons
- covalently; amino acids
- enzymatically; codons
A: covalently; amino acids

Q: Which of the following serves as an "adapter" in protein synthesis and bridges the gap between mRNA and proteins?
- tRNA
- cDNA
- rRNA
- promoter sequences
- DNA
A: tRNA

Q: The codon is found in the:
- template strand of DNA.
- non-template strand of DNA.
- mRNA.
- tRNA.
- rRNA.
A: mRNA.

Q: The tRNA:
- must be recognized by ribosomes.
- must have an anticodon.
- must have an attachment site for the amino acid.
- must be recognized by a specific aminoacyl-tRNA synthetase that adds the correct amino acid.
- All of the above.
A: All of the above.

Q: In Figure 12-03, the portion of the molecule in the figure that contains the anti-codon is:
- 1.
- 2.
- 3.
- 4.
- 5.
A: 3.

Q: In Figure 12-03, the portion of the molecule labeled 5 is:
- the attached amino acid.
- a double-stranded region.
- a single-stranded region.
- the anti-codon.
- the codon.
A: the attached amino acid.

Q: Translocation is the process whereby the __________ moves in order to place the tRNA bound to the growing polypeptide chain in the __________ site, thereby freeing the __________ site for a new aminoacyl-tRNA.
- mRNA; A; P
- ribosome; P; A
- tRNA; P; A
- ribosome; A; P
- tRNA; A; P
A: ribosome; P; A

Q: Following peptide bond formation between the amino acid in the A site on the ribosome and the growing polypeptide chain, the tRNA in the A site:
- releases the growing polypeptide chain.
- picks up another amino acid to add to the chain.
- moves to the P site of the ribosome.
- forms a peptide bond with A site of the ribosome.
- forms a covalent bond with the P site of the ribosome.
A: moves to the P site of the ribosome.

Q: In Figure 13-01, the area of the tryptophan operon labeled 3 is the:
- promoter.
- repressor gene.
- ribosome.
- RNA polymerase.
- None of the above.
A: None of the above.

Q: The structure labeled 7 in Figure 13-01 of the tryptophan operon is:
- an active repressor protein.
- an inactive repressor protein.
- an active RNA polymerase.
- an inactive RNA polymerase.
- A ribosome.
A: an inactive repressor protein.

Q: The promoter in Figure 13-01 is labeled ____________.
- 6
- 3
- 1
- 2
- 7
A: 2

Q: The total DNA in a cell is referred to as the:
- genome.
- cDNA.
- library.
- chromosomal DNA.
- None of the above.
A: genome.