Unit 4

Question 1

A genetic entity that has a DNA genome, binds to a cellular receptor, integrates into the host cell’s genome and is passed to daughter cells during host chromosome replication and cell division is:

Answer 1

temperate bacteriophage

Question 2

Which of the following properties are associated with the enzyme telomerase?
a) may disappear as cells age and go through numerous replication cycles; b) requires an RNA molecule for its designated activity; c) catalyzes the synthesis of a tandemly repeated DNA sequence; d) all of the above; e) none of the above.

Answer 2

D

Question 3

The molecule hemoglobin is a 4 subunit protein containing two copies each of the products of the alpha and beta globin genes. Which levels of protein structure are evidenced for the assembly of hemoglobin?
a) primary structure; b) secondary structure; c) tertiary structure; d) quaternary structure; e) all of the above.

Answer 3

E

Question 4

The enzyme that produces a short RNA molecule that permits the synthesis of an Okazaki fragment is:
a) a primase; b) a ligase; c) a transcriptase; d) a helicase; e) a basketcase.

Answer 4

A

Question 5

Which of the following techniques uses mRNA as the source material for recovering cloned molecules?
a) genomic library construction; b) cDNA library construction; c) PCR; d) nuclear transplantation; e) none of the above.

Answer 5

B, cDNA library construction

Question 6

Which of the following are essential features of a plasmid used for recombinant DNA cloning?
a) origin of replication; b) ability to integrate into bacterial chromosomes; c) ability to cause lysis of the host cell; d) all of the above; e) none of the above.

Answer 6

A

Question 7

A mutation in the rII locus of phage T4 is isolated. This mutant does not revert to wild type. In addition, it fails to complement several different mutations found in both the rIIA and rIIB genes. This mutation is most likely:
a) a missense mutation; b) a nonsense mutation; c) the addition of a single nucleotide; d) a deletion; e) all of the above are equally likely.

Answer 7

D

Question 8

used to localize genes to specific bands in eukaryotic cmsms

Answer 8

in situ hybridization

Question 9

hypermutable site

Answer 9

hot spot

Question 10

the linkage btwn R groups to form a polymer

Answer 10

peptide bond

Question 11

produced during lagging strand synthesis

Answer 11

Okazaki fragment

Question 12

causes mutations by intercalating into DNA

Answer 12

proflavin dyes

Question 13

relieves torsional stress during DNA replication

Answer 13

topoisomerase

Question 14

protein complex that protects cmsm integrity, preventing non-homolgous end joining

Answer 14

shelterin

Question 15

region of DNA ass’d with prokaryotic promoters

Answer 15

pribnow Box

Question 16

repeated consensus sequence of [TTGGGG]n is replicated by a special enzyme

Answer 16

telomere

Question 17

oligonucleotide grid used to monitor gene expression

Answer 17

microarray

Question 18

fluorescent hybridization technique used to localize different genes in the same experiment

Answer 18

FISH

Question 19

“slow or fast stop” phenotypes provided clues to gene function during bacterial DNA replication

Answer 19

temperature sensitive mutations

Question 20

copia elements are an example in Drosophila

Answer 20

transposons

Question 21

protein involved in transcription initiation and promoter binding

Answer 21

sigma factor

Question 22

used to detect mRNA movement from nucleus to cytoplasm in pulse chase experiments

Answer 22

tritiated uridine

Question 23

used to visualize the bacterial chromosome by autoradiography

Answer 23

3H-dTTP

Question 24

T/F: Since E. co/i has a single copy genome, it is impossible to isolate a mutation in a gene
encoding a plotin required for a critical function like DNA replication, since such mutations would be lethal

Answer 24

false

Question 25

T/F: mRNA does not contain a promoter sequence?

Answer 25

True

Question 26

Which of the following would be used for the construction of a cDNA library, but not a genomic library?

Answer 26

reverse transcriptase

Question 27

In bacteriophage lambda, the two strands of DNA can be separated from each other on the basis of their
density, using denaturing CsCl gradients and ultracentrifugation. mRNA synthesized by lambda phage can
be isolated from infected cells, and when allowed to anneal to the denatured DNA, it is observed that both
DNA strands are capable of forming mRNA-DNA duplexes. This observation indicates:
a) bacteriophage lambda contains one long polycistronic mRNA; b) the two strands of lambda DNA must be
identical in sequence; c) all genes in lambda are transcribed off the same DNA strand; d) both strands of the
lambda DNA can serve as a template strand for transcription; e) none of the above.

Answer 27

D

Question 28

E. coli DNA pmrs III:
a)synthesizes a DNA chain in the 5’ to 3’ direction b) is a multisubunit protein complex at the replication fork, c) has 3’ to 5’ exonuclease activity d) all of the above

Answer 28

D

Question 29

What features of plasmid cloning vectors are important for their use in cloning recombinant DNA
molecules?
a) they contain a dominant selectable marker; (b)they contain an origin of replication; c) they contain a
restriction site in a nonessential region of the plasmid genome; ll of the above; e) none of the above.

Answer 29

D

Question 30

the sigma factor of E. coli is required for which function?

Answer 30

binding to the promoter

Question 31

True or false. Using the pyrosequencing technology, a base read occurs when a fluorescent molecule is incorporated into the DNA strand, giving off light of a specific wavelength when illuminated by a laser.

Answer 31

False

Question 32

T/F: Pyrosequencing
technology enzymatically converts
pyrophosphate into ATP, which is then used to enzymatically generate a flash of visible light that is detected if a nucleotide is incorporated.

Answer 32

T

Question 33

What do these describe? provides a “snapshot” of the genes expressed in a particular tissue
isolate mRNA from tissue of interest
convert to d.s. DNA in vitro with reverse transcriptase and Pol I

Answer 33

construction of a cDNA library