Nadia Siddique
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Quiz on Molecular Genetics, created by Nadia Siddique on 17/01/2016.

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Nadia Siddique
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Molecular Genetics

Question 1 of 74

1

The first step in the polymerase chain reaction (PCR) is

Select one of the following:

  • Denaturation

  • Cooling

  • Annealing

  • Primer extension

Explanation

Question 2 of 74

1

In a polymerase chain reaction, a synthetic sequence of nucleotides are involved in

Select one of the following:

  • Denaturing

  • Heating

  • Cooling

  • Copying

  • All of the above

Explanation

Question 3 of 74

1

Bacteria protect themselves from viruses by fragmenting viral DNA upon entry with

Select one of the following:

  • Ligases

  • Endonucleases

  • Methylases

  • Vectors

  • Probes

Explanation

Question 4 of 74

1

When "sticky ends" are paired, they can be joined by

Select one of the following:

  • Restriction Enzymes

  • pSC101

  • Methylases

  • X-gal

  • DNA ligase

Explanation

Question 5 of 74

1

One of the most useful methods for identifying a specific gene is

Select one of the following:

  • Western blot

  • Southern blot

  • Eastern blot

  • Magnetic resonance imaging

  • Thin chromatography

Explanation

Question 6 of 74

1

The Polymerase Chain Reaction is used to:

Select one of the following:

  • amplify a small amount of DNA

  • cleave bacterial plasmids

  • seal "sticky ends"

  • identify target plasmids

  • none of the above

Explanation

Question 7 of 74

1

When tryptophan is present in the medium, the transcription of tryptophan producing genes in E. coli is stopped by a helix-turn-helix regulator binding to the

Select one of the following:

  • trp repressor

  • trp operon

  • trp promoter

  • trp operator

  • trp polymerase

Explanation

Question 8 of 74

1

When tryptophan is present in the environment of E. coli, the tryptophan binds to the

Select one of the following:

  • trp operon

  • trp promoter

  • trp operator

  • trp repressor

  • trp polymerase

Explanation

Question 9 of 74

1

The operon that controls tryptophan producing genes in E. coli consists of _______________

Select one of the following:

  • activator

  • regulator

  • promoter

  • operator

  • repressor

Explanation

Question 10 of 74

1

In order for a gene to be transcribed, RNA polymerase must have access to the DNA helix and be able to bind to the genes

Select one of the following:

  • activator

  • regulator

  • promoter

  • operator

  • repressor

Explanation

Question 11 of 74

1

In the function of the lac operon in E. coli, the lac genes are transcribed in the presence of lactose because

Select one of the following:

  • RNA polymerase binds to the operator

  • the repressor cannot bind to the promoter

  • an isomer of lactose binds to the repressor

  • CAP does not bind to the operator

  • of the absence of cAMP

Explanation

Question 12 of 74

1

The role of methylation of DNA is now viewed as

Select one of the following:

  • interfering with DNA transcription by blocking base pairing between cytosine and guanine

  • complexing with enhancers to prevent transcription

  • prevention of mutation

  • insuring that genes that are turned off, stay off

  • irrelevant to gene transcription

Explanation

Question 13 of 74

1

E. coli is able to use foods other than glucose in the absence of available glucose, because falling levels of glucose cause an increase of

Select one of the following:

  • cAMP

  • CAP

  • lactase

  • glu operon

  • tRNA

Explanation

Question 14 of 74

1

In the absence of glucose, E. coli can import lactose to change into glucose and galactose because CAP binds to the

Select one of the following:

  • cAMP

  • DNA

  • lac operon

  • operator

  • repressor

Explanation

Question 15 of 74

1

Which is not part of the lac operon?

Select one of the following:

  • repressor

  • activator protein

  • operator

  • promoter

  • structural gene

Explanation

Question 16 of 74

1

In an operon the location of the regulatory region occurs ________ the structural genes.

Select one of the following:

  • after

  • within

  • before

Explanation

Question 17 of 74

1

Which of the following is part of an operon?

Select one of the following:

  • structural genes

  • operator

  • promoter

  • a CAP binding site

  • all of the above

Explanation

Question 18 of 74

1

Transcription is initiated when RNA polymerase binds to

Select one of the following:

  • promoter

  • initiator

  • codon

  • transcriptor

Explanation

Question 19 of 74

1

In eukaryotes, there are _______________ codons that specify amino acids

Select one of the following:

  • 21

  • 24

  • 61

  • 64

  • 100

Explanation

Question 20 of 74

1

In eukaryotes, the "start" codon also specifies the amino acid,

Select one of the following:

  • phenylalanine

  • valine

  • methionine

  • aspartate

Explanation

Question 21 of 74

1

In transcription, the nucleotide sequence CAT in DNA would specify _______________ in mRNA.

Select one of the following:

  • TAC

  • GAU

  • CAT

  • GTU

  • GUA

Explanation

Question 22 of 74

1

The genetic code consists of groups of three nucleotides called

Select one of the following:

  • codons

  • introns

  • anticodons

  • reading frame

  • triplets

Explanation

Question 23 of 74

1

The function of tRNA is to

Select one of the following:

  • provide a site for polypeptide synthesis

  • transport amino acids to the ribosome

  • travel to the ribosome to direct the assembly of polypeptides

  • transcribe DNA

  • translate DNA

Explanation

Question 24 of 74

1

In the formation of an initiation complex, a _______________ is positioned first.

Select one of the following:

  • met-tRNA

  • ser-tRNA

  • tyr-rRNA

  • mval-tRNA

  • cyst-tRNA

Explanation

Question 25 of 74

1

The function of mRNA is to

Select one of the following:

  • provide a site for polypeptide synthesis

  • transport amino acids to the ribosome

  • travel to the ribosome to direct the assembly of polypeptides

  • transcribe DNA

  • translate DNA

Explanation

Question 26 of 74

1

The process of _______________ cuts introns from the primary transcript and the final "processed" mRNA is produced.

Select one of the following:

  • RNA cleaving

  • RNA translocation

  • RNA splicing

  • RNA elongation

  • RNA releasing

Explanation

Question 27 of 74

1

In the process of translation,

Select one of the following:

  • a strand of mRNA is formed with nucleotide sequences complementary to those of DNA

  • nucleotide sequences of tRNA are established

  • a polypeptide is formed in response to the rRNA nucleotide sequence

  • rRNA is synthesized with sequences complementary to those of tRNA

  • a polypeptide is formed as dictated by the nucleotide sequence in mRNA

Explanation

Question 28 of 74

1

In mRNA, the series of nucleotides CCC specifies

Select one of the following:

  • serine

  • proline

  • alanine

  • arginine

  • stop

Explanation

Question 29 of 74

1

A molecule of tRNA with the anticodon AAA will transport the amino acid

Select one of the following:

  • phenylalanine

  • lysine

  • glycine

  • leucine

  • alanine

Explanation

Question 30 of 74

1

As polypeptides are formed at the ribosome, elongation continues until _______________ is exposed.

Select one of the following:

  • a release factor

  • an intron

  • a nonsense codon

  • an exon

  • polypeptidases

Explanation

Question 31 of 74

1

Which one of the following is not a kind of RNA?

Select one of the following:

  • mRNA

  • tRNA

  • rRNA

  • nRNA

  • All of the above are kinds of RNA

Explanation

Question 32 of 74

1

The direct result of transcription is

Select one of the following:

  • a duplicate DNA molecule

  • nRNA

  • protein

  • mRNA

  • none of the above

Explanation

Question 33 of 74

1

The direct result of translation is

Select one of the following:

  • duplicate DNA

  • mRNA

  • protein

  • nRNA (nuclear RNA)

  • none of the above

Explanation

Question 34 of 74

1

Which one of the following is not associated with transcription?

Select one of the following:

  • tRNA

  • mRNA

  • nRNA

  • rRNA

  • all of the above

Explanation

Question 35 of 74

1

Which one of the following is not associated with translation?

Select one of the following:

  • tRNA

  • mRNA

  • rRNA

  • anticodons

  • All are involved with translation

Explanation

Question 36 of 74

1

According to Chargaff's rule, the following proportion exists in DNA

Select one of the following:

  • A=G

  • C=G

  • T=G

  • A>T

  • C>G

Explanation

Question 37 of 74

1

The actual synthesis of DNA in E. coli is the function of

Select one of the following:

  • polymerase I

  • primase

  • primer

  • polymerase III

  • ligase

Explanation

Question 38 of 74

1

Since the first nucleotides cannot be linked in a newly synthesized strand in DNA replication, ___________ is required.

Select one of the following:

  • DNA primer

  • DNA ligase

  • DNA polymerase

  • RNA primer

  • helicase

Explanation

Question 39 of 74

1

The fact that some viruses use DNA to direct their heredity was demonstrated by

Select one of the following:

  • finding radioactive sulfur from a bacteriophage in a bacterium

  • finding radioactive phosphorus from a bacterium in a bacteriophage

  • finding that radioactive phosphorus from a bacteriophage had mutated in bacterium

  • finding radioactive phosphorus from a bacteriophage in a bacterium

  • finding radioactive sulfur from a bacterium in a bacteriophage

Explanation

Question 40 of 74

1

Okazaki fragments are used to elongate

Select one of the following:

  • the leading strand toward the replication fork

  • the lagging strand toward the replication fork

  • both strands in both directions

  • the leading strand away from the replication fork

  • the lagging strand away from the replication fork

Explanation

Question 41 of 74

1

In nucleic acids, the free hydroxyl group is attached to the _______________ carbon of the sugar.

Select one of the following:

  • 5'

  • 4'

  • 3'

  • 2'

  • 1'

Explanation

Question 42 of 74

1

A single enzyme is specified by a single

Select one of the following:

  • gene

  • chromosome

  • nucleosome

  • nucleotide

  • histone

Explanation

Question 43 of 74

1

In replication of DNA, the helix is opened and untwisted by

Select one of the following:

  • ribase

  • primase

  • deoxase

  • helicase

  • ligase

Explanation

Question 44 of 74

1

_______________ join DNA fragments to the lagging strand

Select one of the following:

  • telomeres

  • centromeres

  • helicases

  • ligases

  • polymerases

Explanation

Question 45 of 74

1

Which statement about the elongation of the lagging strand during DNA replication is correct?

Select one of the following:

  • It is synthesized in a 3' --> 5' direction.

  • It progresses (grows) toward the replication fork

  • It requires a short RNA primer to proceed.

  • It is synthesized by DNA ligase

  • It is synthesized continuously

Explanation

Question 46 of 74

1

If one side of a DNA molecule contains the following sequence of nucleotides, AGTCCG, the complementary sequence on the other side would be:

Select one of the following:

  • GCCTGA

  • AGTCCG

  • TCAGGC

  • CTGAAT

  • none of the above

Explanation

Question 47 of 74

1

During your summer job at Virotech, you isolate a previously unknown virus. Analysis of its genome reveals that it is composed of a double stranded DNA molecule containing 14% T (thymine). Based on this information, what would you predict the %C (cytosine) to be?

Select one of the following:

  • 14%

  • 28%

  • 36%

  • 72%

  • can't tell!

Explanation

Question 48 of 74

1

The process of acquiring a gene from another organism is called transformation.

Select one of the following:

  • True
  • False

Explanation

Question 49 of 74

1

The Hershey-Chase experiment showed that the virus protein is responsible for directing the production of new viruses.

Select one of the following:

  • True
  • False

Explanation

Question 50 of 74

1

The two sides of the double helix structure of DNA are held together with hydrogen bonds.

Select one of the following:

  • True
  • False

Explanation

Question 51 of 74

1

DNA replication is called semiconservative because half of each of the two new strands of DNA is "old" DNA from the original DNA molecule and half is "new" DNA.

Select one of the following:

  • True
  • False

Explanation

Question 52 of 74

1

Genetic engineering has been used to do all of the following except:

Select one of the following:

  • make plants more resistant to frost

  • make plants more resistant to disease

  • make plants more resistant to herbicides

  • improve the nutritional balance of plants

  • all of the above

Explanation

Question 53 of 74

1

According to Mendel, which of the following cause an organism's size, colour and markings?

Select one of the following:

  • Chromosomes

  • Genes

  • Alleles

  • Factors

Explanation

Question 54 of 74

1

Which term is associated with eukaryotic DNA?

Select one of the following:

  • chrosome

  • histone

  • telomere

  • all of the above

Explanation

Question 55 of 74

1

If 28% of a segment of DNA is composed of guanine, how much of the segment is adenine?

Select one of the following:

  • 7%

  • 22%

  • 28%

  • There is no way to determine this.

Explanation

Question 56 of 74

1

How did the work of Franklin and Wilkins contribute to the discovery of the structure of DNA?

Select one of the following:

  • They determined the rule of base pairing

  • They determined that DNA has an X shape

  • They determined the double helix structure

  • They determined that the strands run antiparallel

Explanation

Question 57 of 74

1

Which of these findings made Watson and Crick confident that their DNA model was correct?

Select one of the following:

  • Chargaff's base-pairing ratios

  • Pauling's three-strand model

  • Franklin's early disagreement with the double helix theory

  • All of the above

Explanation

Question 58 of 74

1

What would have been the results of Meselson and Stahl's experiment if DNA had undergone conservative replication?

Select one of the following:

  • one band containing only 14N

  • one band containing only 15N

  • two bands: one of 15N and 14N

  • three bands: one of 15N, one of 14N, and one of 1:1 14N:15N

Explanation

Question 59 of 74

1

Which characteristics of the structure of DNA results in a lagging strand and a leading strand during DNA replication?

Select one of the following:

  • its phosphate backbone

  • its antiparallel strands

  • the ratio of purines to pyrimidines

  • the full twist every ten nucleotides

Explanation

Question 60 of 74

1

What is the function of DNA ligase in replication?

Select one of the following:

  • It initiates a replication bubble

  • It prevents DNA strands from tangling

  • It places nucleotides to form a new DNA strand

  • It fills gaps on the lagging strand

Explanation

Question 61 of 74

1

Which method do prokaryotes use to compact DNA?

Select one of the following:

  • Spooling around a histone

  • Forming a nucleosome

  • Supercoiling

  • Winding into solenoids

Explanation

Question 62 of 74

1

Where are telomeres located?

Select one of the following:

  • At ends of chromosomes

  • On the leading strand

  • At the replication fork

  • On prokaryotic plasmids

Explanation

Question 63 of 74

1

What is the name of Beadle and Tatum's original hypothesis?

Select one of the following:

  • One gene-one sequence hypothesis

  • One gene-one enzyme hypothesis

  • One gene-one peptide hypothesis

  • One gene-one polypeptide hypothesis

Explanation

Question 64 of 74

1

What is the sequence of information transfer, as outlined by the central dogma?

Select one of the following:

  • DNA -> tRNA -> mRNA --> polypeptide

  • DNA -> mRNA -> tRNA --> polypeptide

  • DNA -> mRNA -> rRNA --> polypeptide

  • DNA -> rRNA -> tRNA --> polypeptide

Explanation

Question 65 of 74

1

Where is the TATA box found?

Select one of the following:

  • In the termination sequence that stops DNA polymerase

  • In the termination sequence that stops RNA polymerase

  • In the promoter that enables the binding of DNA polymerase

  • In the promoter that enables the binding of RNA polymerase

Explanation

Question 66 of 74

1

What happens during capping and tailing?

Select one of the following:

  • A methyl 5' tail and poly(A) cap are added

  • A methyl 3' tail and poly(A) cap are added

  • A methyl 5' cap and poly(A) tail are added

  • A methyl 3' cap and poly(A) tail are added

Explanation

Question 67 of 74

1

How is the lac operon inhibited?

Select one of the following:

  • The lac repressor is not synthesized by the lacl gene

  • RNA polymerase is inhibited by high concentrations of allolactase

  • The lac repressor is inhbited by high concentrations of allolactase

  • Allolactase is not present to bind with the lac repressor

Explanation

Question 68 of 74

1

Which term refers to a point mutation that results in a different amino acid in a particular position?

Select one of the following:

  • Missense mutation

  • Silent mutation

  • Nonsense mutation

  • Frameshift mutation

Explanation

Question 69 of 74

1

What is the molecular tool scientists use to cut a DNA fragment from a larger piece of DNA?

Select one of the following:

  • Restriction enzymes

  • DNA primase

  • Methylase

  • DNA ligase

Explanation

Question 70 of 74

1

After excising a DNA fragment that contains a target gene, what should a molecular biologist do?

Select one of the following:

  • Introduce a vector into a suitable organism

  • Isolate a desired gene or DNA fragment

  • Select the transformed cells

  • Insert the gene into a vector

Explanation

Question 71 of 74

1

Which chemical compound can be used to stain a completed electrophoresis gel?

Select one of the following:

  • Ethidium bromide

  • Loading dye

  • Molecular marker

  • DNA polymerase

Explanation

Question 72 of 74

1

During PCR, double-stranded DNA is separated into two single strands of DNA. What is this step called?

Select one of the following:

  • Splicing

  • Denaturation

  • Extension

  • Annealing

Explanation

Question 73 of 74

1

After 8 PCR cycles, how many target sequences have been synthesized?

Select one of the following:

  • 8

  • 16

  • 240

  • 256

Explanation

Question 74 of 74

1

How does genetic therapy differ from traditional methods of treating a disease?

Select one of the following:

  • It targets the effects of the disease

  • In some cases, it fixes the genetic code itself

  • It reverses the damage done to the body

  • It replaces the need for organ transplant

Explanation

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