Question 1

A double-stranded DNA molecule can be separated into single strands by heating it to 90°C because

Accepted Answer

A) heat disrupts the hydrogen bonds holding the sugar-phosphate backbone together. 
B) DNA is negatively charged. 
C) heat disrupts hydrogen-bonding between complementary nucleotides. 
D) DNA is positively charged.

Question 2

Which portion of an organism's genome is most likely to diverge most rapidly over evolutionary time?

Accepted Answer

A) the noncoding gene regulatory regions. 
B) the noncoding telomeric sequences. 
C) the exons. 
D) the sequences at the intron/exon border.

Question 3

During DNA renaturation, two DNA strands will

Accepted Answer

A) break the covalent bonds that hold the nucleotides together while maintaining the hydrogen bonds that hold the two strands together. 
B) break the hydrogen bonds that hold the two strands together with no effect on the covalent bonds that hold the nucleotides together. 
C) re-form a double helix if the two strands have complementary sequences. 
D) re-form a double helix if the two strands are identical in sequence.

Question 4

Which of the following techniques is not appropriate if you want to examine whether a gene is expressed in a specific tissue?

Accepted Answer

A) in situ hybridization 
B) production of a cDNA library 
C) RNA-Seq 
D) next generation genome sequencing

Question 5

During gel electrophoresis, DNA fragments

Accepted Answer

A) travel through a matrix containing a microscopic network of pores. 
B) migrate toward a negatively charged electrode. 
C) can be visualized without stains or labels. 
D) are separated on the basis of their sequence.

Question 6

Starting with one double-stranded DNA molecule, how many cycles of PCR would you have to perform to produce about 100 double-stranded copies (assuming 100% efficiency per cycle)?

Accepted Answer

A) 2 
B) 7 
C) 25 
D) 100

Question 7

Recombinant DNA technologies involve techniques that permit the creation of custom-made DNA molecules that can be introduced back into living organisms.These technologies were first developed in the

Accepted Answer

A) 1800s. 
B) 1950s. 
C) 1970s. 
D) 2000s.

Question 8

Some plasmids from cDNA libraries can have defects because of the way in which a cDNA library is constructed.For each dilemma (A to D) listed below, indicate which of the outcomes (1 to 4) you might encounter, and explain why.Outcomes may be used more than once. $\begin{array}{llcc}
\underline{  \text { Dilemma }\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad} & \underline{ \text {  Outcomes\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad}  }\
 \text { (A) The mRNA corresponding to the clone you are } &\text { (1) The 5' part of the gene will be missing. } \
 \text {   looking for was degraded at its 5' end by a } &\
 \text {  nuclease.} &\
\
 \text {(B) The mRNA corresponding to the clone you are  } &  \text {(2) The $ 3^{\prime} $ part of the gene will be missing.  }\
 \text { looking for was degraded at its $ 3^{\prime} $ end by a   } &\
  \text { nuclease. } &  \ 
\
 \text { (C) The S'end of the reverse transcriptase product of } &  \text {(3) An internal fragment of the gene will be missing }\
 \text {  the gene you are trying to clone hybridizes to  } &\
 \text { sequences in the middle of the gene. } &\
\
 \text {(D) The gene you are trying to clone has a long  } &  \text {  (4) The gene will be missing from the library.}\
 \text {stretch of A's in the middle of the coding   } &\
 \text {  sequence. } &\
\end{array}$ 
 
Table 10-54

Accepted Answer

The answer of Some plasmids from cDNA libraries can have...

Question 9

Which of the following describes a feature found in bacterial expression vectors but not in cloning vectors?

Accepted Answer

A) origin of replication 
B) cleavage sites for restriction nucleases 
C) promoter DNA sequences 
D) a polyadenylation signal

Question 10

You have been hired to create a cat that will not cause allergic reactions in cat-lovers.Your coworkers have cloned the gene encoding a protein found in cat saliva, expressed the protein in bacteria, and shown that it causes violent allergic reactions in people.But you soon realize that even if you succeed in making a knockout cat lacking this gene, anyone who buys one will easily be able to make more hypoallergenic cats just by breeding them.Which of the following will ensure that people will always have to buy their hypoallergenic cats from you?

Accepted Answer

A) Inject the modified embryonic stem (ES) cells into embryos that have a genetic defect to prevent the mature adult from reproducing. 
B) Implant the injected embryos into a female cat that is sterile as a result of a genetic defect. 
C) Sell only the offspring from the first litter of the female cat implanted with the injected embryos. 
D) Surgically remove the sexual organs of all the knockouts before you sell them.

Question 11

You have a circular plasmid that can be cut by the restriction nuclease HindIII, as diagrammed in Figure 10-4.  Figure 10-4
If you were to cut this circular piece of DNA with HindIII, which of the answers below best predicts what you would get?

Accepted Answer

A) one linear piece of DNA 
B) two circular pieces of DNA 
C) two semicircular pieces of DNA 
D) two linear pieces of DNA

Question 12

How does the Cas9 system target where it produces a double-strand break in the DNA?

Accepted Answer

A) A guide RNA molecule is associated with Cas9 and will direct Cas9 to bind at sequences complementary to the guide RNA. 
B) The Cas9 protein contains amino acids that can interact with specific sequences in the DNA, targeting Cas9 to those specific sites. 
C) The Cas9 protein binds to a recombinase, allowing it to disable the gene of interest. 
D) A guide RNA molecule associated with Cas9 provides the catalytic activity to cleave the DNA where Cas9 binds.

Question 13

Which of the following statements about Illumina sequencing is FALSE?

Accepted Answer

A) The nucleoside triphosphates that are used have a fluorescent marker. 
B) The nucleoside triphosphates that are used have a 3′ chemical group that will terminate DNA synthesis. 
C) The termination of DNA synthesis by the nucleoside triphosphates that are used is reversible. 
D) Both normal and modified nucleoside triphosphates are used to synthesize DNA.

Question 14

Which of the restriction nucleases listed below can potentially cleave a segment of cDNA that encodes the peptide KIGDACF? $\text { The Genetic Code }$
\(\begin{array}{|l|l|l|l|l|}
\hline & \text { U } & \text { C } & \text { A } & \text { G } \
\hline &\text { UUU Phe (F) } & \text { UCU Ser (S) } & \text { UAU Tyr (Y) } & \text { UGU Cys (C) } \
&\text { UUC - } & \text { UCC - } & \text { UAC - } & \text { UGC - } \
 \text { U } &\text { UUA Leu (L) } & \text { UCA -- } & \text { UAA Stop } & \text { UGA Stop } \
&\text { UUG - } & \text { UCG - } & \text { UAG Stop } & \text { UGG Trp (W) } \
\hline &\text { CUU Leu (L) } & \text { CCU Pro (P) } & \text { CAU His (H) } & \text { CGU Arg (R) } \
&\text { CUC - } & \text { CCC - } & \text { CAC - } & \text { CGC - } \
 \text { C}&\text { CUA - } & \text { CCA - } & \text { CAA Gin (Q) } & \text { CGA - } \
&\text { CUG }- & \text { CCG }- & \text { CAG }- & \text { CGG }- \
\hline &\text { AUU Ile (I) } & \text { ACU Thr (T) } & \text { AAU Asn (N) } & \text { AGU Ser (S) } \
&\text { AUC - } & \text { ACC - } & \text { AAC - } & \text { AGC - } \
 \text { A}&\text { AUA - } & \text { ACA - } & \text { AAA Lys (K) } & \text { AGA Arg (R) } \
&\text { AUG Met (M) } & \text { ACG - } & \text { AAG - } & \text { AGG - } \
\hline &\text { GUU Val (V) } & \text { GCU Ala (A) } & \text { GAU Asp (D) } & \text { GGU Gly (G) } \
&\text { GUC - } & \text { GCC - } & \text { GAC - } & \text { GGC - } \
 \text { G}&\text { GUA - } & \text { GCA - } & \text { GAA Glu (E) } & \text { GGA - } \
&\text { GUG - } & \text { GCG - } & \text { GAG - } & \text { GGG - } \
\hline
\end{array}\) 
Table 10-56 $\begin{array}{cc}
 \underline{ \text { Restriction Nuclease} } &\underline{ \text {Recognition Sequence  }} \
 \text {EcoRI  } &\text { GAATTC }\
 \text { HindIII } &\text {AAGCTT  }\
 \text { Nsil } &\text { ATGCAT }\
\end{array}$

Accepted Answer

The answer of Which of the restriction nucleases listed below...

Question 15

Figure 10-25 shows a restriction map of a piece of DNA containing your favorite eukaryotic gene.The arrow indicates the position and orientation of the gene in the DNA.In part (B) of the figure are enlargements showing the portions of the DNA whose sequences have been used to make PCR primers A, B, C, and D.Which primer or primers can be used to amplify the gene? (A)

(B)
 Figure 10-25

Accepted Answer

A) primers A and B 
B) primers A and C 
C) primers A and D 
D) primer A alone

Question 16

Which of the following statements about PCR is FALSE?

Accepted Answer

A) PCR uses a DNA polymerase from a thermophilic bacterium. 
B) PCR is particularly powerful because after each cycle of replication, there is a linear increase in the amount of DNA available. 
C) For PCR, every round of replication is preceded by the denaturation of the double-stranded DNA molecules. 
D) The PCR will generate a pool of double-stranded DNA molecules, most of which will have DNA from primers at the 5′ ends.

Question 17

You are interested in a single-stranded DNA molecule that contains the following sequence:
5′- .....GATTGCAT....-3′
Which molecule will hybridize to your sequence of interest?

Accepted Answer

A) 5′-GATTGCAT-3′ 
B) 5′-TACGTTAG-3′ 
C) 5′-CTAACGTA-3′ 
D) 5′-ATGCAATC-3′

Question 18

The Cas9 enzyme used in the CRISPR system

Accepted Answer

A) was created by scientists by modifying restriction enzymes. 
B) was discovered in bacteria as part of a mechanism to protect themselves from foreign DNA. 
C) was found as part of a natural mechanism used by plants to protect themselves from viruses. 
D) was found in cultured mouse embryonic stem (ES) cells.

Question 19

The sequencing of the human genome was a technological accomplishment.Which of the following did NOT contribute to the sequencing of the human genome in the early 2000s?

Accepted Answer

A) shotgun sequencing 
B) restriction site mapping of BACs 
C) automated Sanger sequencing 
D) Illumina sequencing

Exam 10: Analyzing the Structure and Function of Genes