Deck 11: DNA Biology and Technology

Question 1

This figure represents ________.

A) replication
B) translation
C) transcription
D) transformation
E) base pairing

Answer 1

A
Explanation: This figure shows the semiconservative replication of DNA.

Question 2

For a DNA strand that contains the sequence AGT in the 5' to 3' direction, what nucleotides are found on the other DNA strand in the 5' to 3' direction?

A) ACT
B) TGA
C) AGT
D) TCA
E) GTA

Answer 2

A
Explanation: By Chargaff's rules, T hydrogen bonds with A, C with G, and A with T. Since the opposite strand runs antiparallel, the correct order of these nucleotides is ACT.

Question 3

What chemical force must be overcome in order to separate the two DNA strands during replication?

A) hydrophobic interactions
B) intrastrand folding
C) ionic bonds
D) phosphodiester bonds
E) hydrogen bonds

Answer 3

E
Explanation: DNA helicase helps to disrupt the hydrogen bonds between base pairs that hold the two strands together.

Question 4

The three steps that are required for DNA replication are

A) unwinding, complementary base pairing, and joining.
B) base doubling, unwinding, and joining.
C) complementary base pairing, transcription, and translation.
D) unwinding, transcription, and translation.
E) unwinding, base doubling, and base pairing.

Question 5

For a DNA strand composed of the sequence AGT in the 5' to 3' direction, the free phosphate is on the ____ nucleotide and the free hydroxyl is on the ____ nucleotide.

A) T; A
B) A; G
C) A; A
D) G; T
E) A; T

Question 6

If an organism's DNA contains 20% adenine nucleotides, what percentage of its DNA is composed of thymine nucleotides?

A) 10%
B) 15%
C) 20%
D) 30%
E) 40%

Question 7

Which of the following enzymes is needed to seal breaks in the sugar-phosphate backbone during replication?

A) DNA polymerase
B) RNA polymerase
C) RNA ligase
D) helicase
E) DNA ligase

Question 8

DNA replication is called semiconservative because

A) one of the two resulting DNA molecules is new.
B) the two resulting DNA molecules each have one new DNA strand and one old strand from the original DNA molecule.
C) both of the resulting DNA molecules are composed of new strands of nucleotides.
D) no extra nucleotides are incorporated into the replicated DNA molecules.
E) the sequence of nucleotides in one strand is conserved, whereas the new DNA molecule consists of a unique sequence of nucleotides

Question 9

For a DNA strand that is 2 nucleotides long, how many different sequences are possible?

A) 2
B) 4
C) 8
D) 16
E) 64

Question 10

Which of the following is an incorrect match?

A) transcription - removal of introns
B) translation - polypeptide formation
C) transcription - tRNA formation
D) translation - mRNA binding to rRNA
E) replication - copying of DNA

Question 11

Which base is found in DNA, but not in RNA?

A) cytosine
B) uracil
C) thymine
D) adenine
E) guanine

Question 12

If RNA polymerase malfunctions,

A) one of the subunits of rRNA will not be transcribed from DNA.
B) amino acids will not be joined to their tRNA.
C) mRNA cannot bind to rRNA.
D) an mRNA will not be formed.
E) mRNA cannot copy itself.

Question 13

The x-ray diffraction pattern of DNA discovered by Rosalind Franklin showed that DNA

A) is helical.
B) has a repeated pattern.
C) is both helical and has a repeated pattern.
D) contains beta sheets arranged in a repeated pattern.
E) contains alpha helices and beta sheets.

Question 14

If an organism's DNA contains 17% adenine nucleotides and 33% guanine nucleotides, what percentage of its DNA is composed of cytosine nucleotides?

A) 8.5%
B) 17%
C) 25%
D) 33%
E) 50%

Question 15

RNA differs from DNA because RNA

A) is double-stranded, whereas DNA is not.
B) may double back and base pair with itself, whereas DNA does not.
C) is never single-stranded, whereas DNA may or may not be.
D) can self-replicate, whereas DNA replication requires enzymes.
E) is replicated along with DNA, but does not require strand separation like DNA does.

Question 16

A defect in DNA ligase would most likely cause

A) normal replication, but gaps remain in the sugar-phosphate DNA backbone.
B) failure to remove introns from the primary mRNA.
C) incompletely processed primary mRNA that does not get translated properly.
D) translation to initiate normally, but fail to proceed to elongation.
E) DNA strands to separate normally, but fail to join nucleotides in the growing nucleotide chain.

Question 17

The central dogma of molecular biology states that the information contained within genes flows in which direction?

A) DNA to DNA to protein
B) mRNA to DNA to protein
C) DNA to mRNA to protein
D) DNA to tRNA to mRNA to protein
E) DNA to rRNA to protein

Question 18

During the elongation cycle of translation, the A site on a ribosome functions in

A) receiving a new tRNA with the correct amino acid.
B) holding a polypeptide as amino acids are added.
C) attaching the small subunits of rRNA to the large subunit.
D) releasing the completed polypeptide.
E) processing the rRNA.

Question 19

According to Chargaff's rules, ___ always pairs with ____, and _____ always pairs with _____.

A) A; G; T; C
B) A; T; G; C
C) A; C; G; T
D) C; T; G; A
E) G; U; A; C

Question 20

If an organism's DNA contains 20% adenine nucleotides, what percentage of its DNA is composed of guanine nucleotides?

A) 10%
B) 15%
C) 20%
D) 30%
E) 40%

Question 21

A transposon may cause a mutation if it

A) jumps into an exon of another gene.
B) jumps into an intron of another gene.
C) jumps into an intergenic DNA sequence.
D) remains trapped within an intergenic DNA sequence.
E) interacts with a physical mutagen.

Question 22

During translation, initiation occurs normally, but elongation fails to occur. Which process is mostly likely faulty?

A) translocation of ribosome
B) binding of tRNA-methionine to start codon
C) association of the small and large ribosomal subunits
D) processing of primary mRNA
E) joining of nucleotides

Question 23

Which of the following is not an application of transgenic organisms?

A) bacteria that degrade sludge
B) corn plants that are resistant to herbicides
C) bacteria that undergo mutations frequently
D) cattle that secrete therapeutic proteins into their milk
E) carrots that produce influenza virus proteins that can be used as vaccines

Question 24

Which of the following processes does not occur within the nucleus?

A) DNA replication
B) transcription
C) intron removal
D) translation
E) primary mRNA splicing

Question 25

Figure:
The sequence of the peptide that would result from transcribing and translating the gene pictured would be

A) Tyr-Ala-Asn.
B) Ile-Ser-Val.
C) no peptide would be made, the first codon means "stop."
D) Met-Arg-Leu.
E) Tyr-Ser-Val.

Question 26

Which of the following allows a cell to decipher the genetic code?

A) rRNA
B) tRNA
C) mRNA
D) DNA
E) protein

Question 27

Which of the following is not an application of polymerase chain reaction?

A) production of many copies of an unknown piece of DNA
B) making copies of a foreign gene for use in making recombinant DNA
C) DNA fingerprinting of a crime suspect
D) linking two DNA molecules together
E) amplifying mitochondrial DNA sequences

Question 28

Which process requires the participation of all three types of RNA?

A) transcription
B) translation
C) RNA processing
D) replication
E) complementary base pairing

Question 29

Which of the following mutations would cause early termination of translation of the gene pictured?

A) Change the 4th nucleotide of the top strand from C to T, and change the 4th nucleotide of the bottom strand from G to A
B) Change the 5th nucleotide of the top strand from G to C, and change the 4th nucleotide of the bottom strand from C to G
C) Change the 4th nucleotide of the top strand from C to A, and change the 4th nucleotide of the bottom strand from G to T
D) Change the 6th nucleotide of the top strand from A to T, and change the 4th nucleotide of the bottom strand from T to A
E) Change the last nucleotide of the top strand from A to G, and change the 4th nucleotide of the bottom strand from T to C

Question 30

The stages of translation are

A) transcription, mRNA processing, and termination.
B) DNA replication, transcription, and termination.
C) initiation, transcription, elongation cycle, and termination.
D) initiation, elongation cycle, and termination.
E) initiation, transcription, mRNA processing, and termination.

Question 31

The information contained within a gene is not directly copied into which of the following chemical forms?

A) tRNA, rRNA
B) mRNA, tRNA
C) rRNA, protein
D) mRNA, protein
E) tRNA, protein

Question 32

A silent mutation is more likely to occur as a result of

A) a frameshift mutation.
B) a point mutation that does not change the amino acid encoded within the gene.
C) the movement of a transposon into an exon.
D) a point mutation that alters the amino acid encoded within the gene.
E) a large dose of radiation.

Question 33

Using three bases to represent each amino acid in a polypeptide

A) ensures that all amino acids are represented at least once by the code.
B) ensures that other organisms can read the code too.
C) ensures that DNA can replicate properly.
D) prevents the wrong amino acid from being incorporated into a protein.
E) prevents early termination of transcription.

Question 34

Mutations are uncommon because

A) DNA repair enzymes often repair errors.
B) physical mutagens such as X-rays seldom damage DNA.
C) DNA is able to repair itself over time.
D) frameshift mutations occur very frequently.
E) transposons are constantly moving throughout the genome.

Question 35

Which of the following is most likely to cause no difference in phenotype between two individuals?

A) variation of order of bases within a gene
B) a transposon inserted into a gene
C) possessing an extra copy of a gene
D) a frameshift mutation within a gene
E) variation of order of bases within an intergenic sequence

Question 36

DNA replication makes a(n) ____ copy of the DNA strand, while transcription makes a(n) ____ copy of the DNA strand.

A) mRNA; DNA
B) DNA; mRNA
C) DNA; tRNA
D) mRNA; tRNA
E) mRNA; rRNA

Question 37

Which of the following sequences of events in the production of recombinant DNA are in the correct order?

A) mix DNA with plasmid DNA, cut with restriction enzymes, add DNA ligase
B) add DNA ligase, cut DNA with restriction enzymes, mix DNA with plasmid DNA
C) cut DNA with restriction enzymes, mix DNA with plasmid DNA, add DNA ligase
D) mix DNA with plasmid DNA, add DNA ligase, cut with restriction enzymes
E) cut with restriction enzymes, add DNA ligase, mix DNA with plasmid DNA

Question 38

Failure to remove introns from a primary mRNA would most likely cause

A) irregularities in transcription.
B) abnormal translation.
C) DNA to mutate.
D) DNA replication to fail.
E) transcription to terminate early.

Question 39

Figure:
The sequence of the mRNA that would result from transcribing the gene pictured would be ___________.

A) AUGCGAUUA
B) AUUAGCGUA
C) UACGCUAAU
D) UAAUCGCAU
E) ATGCGATTA

Question 40

tRNAs carrying the correct amino acid recognize the proper codons on the mRNA because

A) the anticodon of the tRNA hydrogen binds to the codon of the mRNA by complementary base pairing.
B) the codon of the tRNA binds to the anticodon of the ribosome by complementary base pairing.
C) the anticodon of the tRNA carries the correct amino acid.
D) the amino acid binds to the anticodon of the mRNA and brings the correct tRNA with it.
E) the codon of the mRNA binds the correct amino acid, and the tRNA stabilizes this interaction.

Question 41

The two "sticky ends" illustrated here can bind each other by complementary base pairing.

Question 42

The genetic code in bacteria is different than the genetic code in animals and plants.

Question 43

_____ is the study of the structure and function of cellular proteins and their interactions; _______ may be employed to us computer algorithms to aid this process.

A) Proteomics; bioinformatics
B) Comparative genomics; bioinformatics
C) Genomics; proteomics
D) Proteomics; comparative genomics
E) Comparative genomics; proteomics

Question 44

Transgenic plants may have genes from animals inserted into their DNA.

Question 45

An extra three nucleotides inserted into a gene will cause a frameshift mutation.

Question 46

When DNA fingerprinting is performed, why might an individual possess two different numbers of repeats for the same chromosomal region?

A) Intergenic DNA may vary from one cell to another in the same individual.
B) The individual has different numbers of the same repeated sequence on each homologous chromosome.
C) The sample is contaminated with the DNA of another individual.
D) Each sister chromatid of a chromosome may contain different numbers of repeats.
E) It is not possible for this to occur.

Question 47

mRNA must be processed in the cytoplasm before being used in protein synthesis.

Question 48

The steps involved in a single PCR cycle, in the correct order, are

A) cool to allow DNA strands to anneal, heat to allow primer to anneal, cool to allow DNA polymerase to copy DNA.
B) heat to denature DNA strands and for primer to anneal, cool to allow DNA polymerase to copy DNA.
C) heat to denature DNA strands, cool to allow primer to anneal and to allow DNA polymerase to copy DNA.
D) cool to denature DNA strands, heat to allow primer to anneal, cool to allow DNA polymerase to copy DNA.
E) cool to allow primer to anneal, heat to denature DNA strands, cool to allow DNA polymerase to copy DNA.

Question 49

The two DNA strands must be separated before DNA replication or transcription can occur.

Question 50

Mutations within genes always result in non-functional proteins.