Deck 9: Microbial Genetics

Question 1

The enzymes that help pack DNA into the cell by coiling the DNA into a tight bundle are

A)DNA ligases.
B)DNA polymerases.
C)DNA helicases.
D)DNA gyrases.
E)primases.

Answer 1

D

Question 2

This molecule is transcribed from the DNA template strand and later translated.

A)ribosomal RNA
B)messenger RNA
C)transfer RNA
D)primer RNA
E)protein

Answer 2

B

Question 3

Among the microorganisms, various genomes can include:

A)chromosomes.
B)plasmids.
C)mitochondrial DNA.
D)chloroplast DNA.
E)All of the choices are correct.

Answer 3

E

Question 4

The site where the old DNA strands separate and new DNA strands will be synthesized is called the

A)primer.
B)Okazaki fragment.
C)template.
D)rolling circle.
E)replication fork.

Question 5

All of the following pertain to nitrogenous bases, except:

A)they form pairs by hydrogen bonding.
B)guanine pairs with uracil.
C)adenine pairs with thymine.
D)cytosine and thymine are pyrimidines.
E)allows variation from one nucleotide to another which creates the encoded information.

Question 6

The antiparallel arrangement within DNA molecules refers to

A)each base bonding at the 1' position of the sugar.
B)a purine always bonding to a pyrimidine.
C)one helix strand that runs from the 5' to 3' direction and the other strand runs from the 3' to 5' direction.
D)an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.
E)None of the choices are correct.

Question 7

Which enzyme is mismatched with its function in DNA replication?

A)gyrase - supercoiling DNA
B)RNA polymerase - synthesizes RNA primers
C)ligase - final sealing of DNA nicks in DNA
D)DNA polymerase I - removes primer
E)DNA polymerase III - Adding bases to the new DNA chain

Question 8

Semiconservative replication refers to

A)each base bonding at the 1' position of the sugar.
B)a purine always bonding to a pyrimidine.
C)one helix strand that runs from the 5' to 3' direction and the other strand runs from the 3' to 5' direction.
D)an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.
E)None of the choices are correct.

Question 9

Which is incorrect about purines?

A)only found in DNA, not in RNA
B)are nitrogenous bases
C)always paired with a specific pyrimidine
D)include adenine and guanine
E)found within nucleotides

Question 10

The DNA of microorganisms is made up of subunits called

A)histones.
B)amino acids.
C)nucleotides.
D)mRNA.
E)polymerases.

Question 11

Which enzyme fills in the spaces between the Okazaki fragments with the correct nucleotides?

A)DNA ligases
B)DNA polymerases
C)DNA helicases
D)DNA gyrases
E)primases

Question 12

The duplication of a cell's DNA is called

A)mitosis.
B)replication.
C)transcription.
D)translation.
E)mutation.

Question 13

The RNA molecules that carry amino acids to the ribosomes during protein synthesis are called

A)ribosomal RNA.
B)messenger RNA.
C)transfer RNA.
D)primer RNA.
E)ribozymes.

Question 14

DNA polymerase III

A)is needed for adding nucleotides during mRNA synthesis.
B)synthesizes new DNA only in the 5' to 3' direction.
C)cannot add nucleotides to the lagging strand.
D)synthesizes an RNA primer.
E)All of the choices are correct.

Question 15

All of the following pertain to transcription, except it:

A)occurs on a ribosome in the cytoplasm.
B)occurs before translation.
C)requires RNA polymerase.
D)requires a template DNA strand.
E)is part of the process of protein synthesis.

Question 16

Eukaryotic chromosomes differ from prokaryotic chromosomes because only eukaryotes have

A)histone proteins.
B)chromosomes in a nucleus.
C)several to many chromosomes.
D)elongated, not circular, chromosomes.
E)All of the choices are correct.

Question 17

The enzymes that can proofread replicating DNA, detect incorrect bases, excise them, and correctly replace them are

A)DNA ligases.
B)DNA polymerases.
C)DNA helicases.
D)DNA gyrases.
E)primases.

Question 18

Which of the following is incorrect about transfer RNA?

A)it has a bottom hairpin loop with an anticodon.
B)an anticodon is complementary to a codon.
C)it contains a binding site for an amino acid.
D)the initiator tRNA that binds to the P site has the anticodon UAC.
E)the initiator tRNA in bacteria carries tryptophan.

Question 19

RNA molecules differ from DNA molecules because only RNA

A)has ribose.
B)has uracil.
C)is typically one strand of nucleotides.
D)does not have thymine.
E)All of the choices are correct.

Question 20

Groups of three consecutive bases along the DNA of a gene have the code for one

A)protein.
B)nucleotide.
C)amino acid.
D)purine.
E)None of the choices are correct.

Question 21

Individuals with xeroderma pigmentosa lack a functioning

A)photolyase.
B)DNA polymerase III.
C)DNA ligase.
D)ribozyme.
E)RNA polymerase.

Question 22

Synthesis of an inducible enzyme requires

A)repressor alone bound to operator.
B)substrate bound to repressor.
C)substrate bound to promoter.
D)corepressor and repressor binding to the operator.
E)None of the choices are correct.

Question 23

Which is incorrect about inducible operons?

A)they have genes turned off by a buildup of end product.
B)they are often for catabolic pathways.
C)they are normally turned off.
D)they are turned on by the substrate of the enzyme.
E)they include the lac operon.

Question 24

Which type of mutation leads to a frameshift mutation?

A)missense
B)deletion
C)nonsense
D)base substitution
E)All of the choices are correct.

Question 25

Which of the following is incorrect about animal viruses?

A)viral mRNA is translated on host cell ribosomes
B)replication of viral RNA occurs in the host nucleus
C)host tRNA's are used in viral translation
D)host DNA polymerase often participates in viral DNA replication
E)oncogenic viruses integrate their DNA into host DNA and can initiate cancer

Question 26

A sequence of bases on a gene that does not code for protein is called a/an

A)promoter.
B)operator.
C)operon.
D)exon.
E)intron.

Question 27

Much of what was previously thought to be "junk" DNA has been found to have which purpose?

A)It codes for antibiotic resistance proteins.
B)It codes for repressor proteins.
C)It codes for RNA regulatory molecules.
D)It codes for repair enzymes to fix mutations.
E)None of the choices are correct.

Question 28

The non-transcribed region of DNA to which RNA polymerase binds to initiate transcription is called the

A)promoter.
B)operator.
C)operon.
D)exon.
E)intron.

Question 29

A mutation that changes a normal codon to a stop codon is called a

A)point mutation.
B)silent mutation.
C)back mutation.
D)missense mutation.
E)nonsense mutation.

Question 30

If a codon for alanine is GCA, then the anticodon is

A)GCA.
B)CGT.
C)ACG.
D)CGU.
E)UGC.

Question 31

Which of the following is incorrect about termination codons?

A)they are also called nonsense codons
B)where the bond between the final tRNA and the polymerase is broken
C)they include AUG
D)they include UAA, UAG, UGA
E)they do not have corresponding tRNA

Question 32

Bacterial conjugation involves

A)bacteriophage carrying donor DNA to the recipient cell.
B)a donor cell with a plasmid and a pilus.
C)naked DNA fragments from a lysed donor cell are taken up by a recipient cell.
D)new progeny cells with genes from two parent bacterial cells.
E)None of the choices are correct.

Question 33

All of the following pertain to RNA virus replication, except:

A)positive-sense viruses first replicate a negative strand as a template.
B)retroviruses synthesize DNA from their RNA genome.
C)retroviruses carry reverse transcriptase into the host cell.
D)negative-sense viruses directly undergo translation.
E)All of the choices are correct.

Question 34

The Ames test is designed to

A)determine the rate of DNA replication in various bacterial species.
B)detect the presence of a prophage in a cell.
C)detect if a cell is infected by a virus.
D)determine if a cell is resistant to an antibiotic.
E)detect chemicals with carcinogenic potential.

Question 35

The development of virulent, toxin-producing bacterial strains due to the presence of a temperate phage can occur in

A)bacterial conjugation.
B)transformation.
C)generalized transduction.
D)specialized transduction.
E)All of the choices are correct.

Question 36

Which is incorrect about pyrimidines?

A)are only found in DNA, not in RNA
B)they are always paired with a specific purine
C)they include cytosine and thymine
D)they are found within nucleotides
E)they are nitrogenous bases they

Question 37

The following pertain to ribosomes during protein synthesis, except they:

A)contain codons within their rRNA molecules.
B)participate only in translation.
C)bind to the 5' end of mRNA by their small subunit.
D)use their large subunit to supply enzymes for peptide bonding.
E)shift to the right along the mRNA strand from one codon to the next.

Question 38

Split genes

A)are common in prokaryotes and eukaryotes.
B)only have exons initially transcribed to mRNA.
C)have introns located only at the beginning and end of a coding region.
D)use spliceosomes to excise introns and then join exons.
E)All of the choices are correct.

Question 39

The operon segment composed of the gene that codes for a protein repressor is called the

A)operator.
B)structural locus.
C)regulator.
D)promoter.
E)None of the choices are correct.

Question 40

All of the following are products of transcription, except:

A)rRNA.
B)mRNA.
C)DNA.
D)tRNA.
E)All of the choices are products of transcription.

Question 41

Transduction utilizes bacteriophages to carry DNA from a donor cell to a recipient cell.

Question 42

All of the following are true about mutations, except:

A)they are always detrimental to the organism they occur in.
B)they occur in the DNA.
C)if not repaired, they become part of the gene pool.
D)they may lead to an incorrect protein being made.
E)they can create variants in a population.

Question 43

DNA photolyase, in the presence of visible light, can repair DNA damage due to ultraviolet radiation.

Question 44

An example of epigenetics is when methyl groups attach to certain nucleotides to control transcription.

Question 45

The smallest unit of heredity is a chromosome.

Question 46

Each nucleotide is composed of one phosphate, one 5-carbon _____, and one _____ base.

Question 47

Viruses with DNA for their nucleic acid can have either double-stranded DNA or single-stranded DNA.

Question 48

Which of the following is not true about transposons?

A)They contain DNA that codes for their own removal and insertion.
B)They can move from a chromosome to another chromosome.
C)They can move from a chromosome to a plasmid.
D)They are rare among prokaryotic and eukaryotic cells.
E)They can replicate themselves before jumping to the next location.

Question 49

Lactose is a corepressor in the lac operon.

Question 50

Transcription and translation occur ___ in prokaryotes.

A)in different organelles
B)simultaneously
C)in the nucleus
D)only on the ribosomes

Question 51

Induced mutations result from errors in DNA replication.

Question 52

In order for a retrovirus to insert itself into the host's DNA, it must do which of the following?

A)DNA →DNA
B)DNA →RNA
C)RNA →RNA
D)RNA →DNA
E)RNA →protein

Question 53

The _____ is all of the genetic material of a cell.

Question 54

The on/off switch for transcription in the lactose operon is called the regulator.

Question 55

Individuals with xeroderma pigmentosa cannot repair mutations caused by

A)nitrous acid.
B)acridine dyes.
C)ultraviolet light.
D)ethidium bromide.
E)bisulfite.

Question 56

In bacteria, initiator tRNA carries formyl methionine.

Question 57

In Griffith's experiments with Streptococcus pneumonia rough non-encapsulated Streptococci were converted into to smooth encapsulated Streptococci in the presence of the heat killed smooth encapsulated Streptococci.What is the term that describes this process?

A)transduction
B)conjugation
C)transformation
D)cloning

Question 58

If the DNA sequence is ATTCCGGA, the mRNA transcript would be

A)TAAGGCCT.
B)UAAGGCCU.
C)ATTCCGGA.
D)GUUAATTG.
E)CAAGGUTA.

Question 59

Repressible operons are normally in the on mode in the cell.

Question 60

A missense mutation can cause no significant alteration in protein functions.

Question 61

Each _____ is a specific segment of the DNA with the code for production of one functional product.

Question 62

During replication, each parent DNA strand serves as a _____ for synthesis of new DNA strands.

Question 63

Compare and contrast the characteristics of genetic material, including its chemical structure, organization, and packaging found in eukaryotes, prokaryotes, and viruses.

Question 64

Bacterial resistance to antimicrobial drugs is on the increase.Using your knowledge of microbial genetics, discuss at least 2 specific cell mechanisms that would allow development of antimicrobial resistance.

Question 65

Discuss the interrelationship of DNA, RNA, and proteins in the cell.Explain the specific underlying cellular mechanisms of this relationship.

Question 66

A permanent, inheritable change in the genetic information is called a _____.

Question 67

Compare and contrast the 3 bacterial gene transfers with DNA recombination.Explain why these are not reproduction, and why they are important to bacterial species.

Question 68

A nucleosome is a linear chromosome wound around the _____.

Question 69

A screening system called the _____ test is used for detecting chemicals with carcinogenic potential.

Question 70

Base pairs in DNA are held together by _____ bonds.

Question 71

Gene regulation can involve a protein repressor that blocks _____ from initiating transcription.

Question 72

Repressible operons require that a _____ bind to the repressor protein before it can bind to the operator.

Question 73

Compare and contrast the components and specific regulatory events of the lac operon and the arg operon.