Deck 10: Microbial Genetics and Genetic Engineering

Question 1

The three fundamental functions of genetic material in a cell include ________. (Select all that apply)

A) storage of information needed for making all the parts of a living organism
B) accurate replication of the information so that it may be passed on to the next generation
C) opportunity for genetic variation to increase diversity in populations so that they will have a chance to survive environmental change
D) to have enzymatic activity necessary for the metabolism of the cell

Answer 1

A,B,C

Question 2

The basic structure of the double DNA helix includes ________. (Select all that apply)

A) two separate nucleotide helices twisted together
B) strands are held together by nitrogen-containing base pairs bonded together via hydrogen bonds
C) complementary pairing of nitrogen-containing base pairs with adenine pairing with thymine and cytosine with guanine
D) polynucleotide chains running parallel to each other

Answer 2

A,B,C

Question 3

Major differences between DNA and RNA include all of these except ________.

A) DNA uses nucleotides containing uracil while RNA uses nucleotides containing thymine
B) DNA is usually found in a double helix while RNA usually is single-stranded
C) DNA has nucleotides containing deoxyribose while RNA has nucleotides containing ribose
D) the nucleotide sequences found in DNA are used for self-replication, while the nucleotide sequence in RNA is used to direct protein synthesis

Answer 3

A

Question 4

A plasmid ________.

A) is synthesized from part of the chromosome
B) is a small, self-replicating rings of DNA found in some bacteria
C) codes for the entire genetic makeup of an organism
D) are sets of three nucleotides making up RNA

Question 5

Codons are ________.

A) part of a tRNA molecule
B) small, self-replicating rings of DNA found in some bacteria
C) the entire genetic makeup of an organism
D) sets of three nucleotides making up the coding portion of mRNA

Question 6

The function of DNA Helicase is ________.

A) DNA proofreading
B) unwinding double-stranded DNA
C) linking Okazaki fragments together
D) to remove and replace RNA primers with nucleotides

Question 7

The function of DNA polymerase I is ________.

A) synthesis of RNA primers
B) unwinding double-stranded DNA
C) linking Okazaki fragments together
D) to remove and replace RNA primers with nucleotides

Question 8

________ removes supercoils so DNA strands can continue to unwind.

A) DNA Helicase
B) DNA gyrase
C) DNA polymerase III
D) DNA polymerase I

Question 9

In the illustration below, what is the function of item r?

A) Bind to single stranded DNA to keep the separated strands from reannealing.
B) Separate the DNA strands.
C) Make a DNA copy of the template strand of DNA.
D) Remove supercoils that form as a result of unwinding the DNA double helix.

Question 10

In the illustration below, what is the function of item u?

A) Make an RNA primer.
B) Separate the DNA strands.
C) Make a DNA copy of the template strand of DNA.
D) Link Okazaki fragments together.

Question 11

In the illustration below, what is the function of item q?

A) Make an RNA primer.
B) Separate the strands of the DNA double helix.
C) Make a DNA copy of the template strand of DNA.
D) Bind to single stranded DNA to keep the separated strands from reannealing.

Question 12

The DNA strand that is used as pattern for mRNA using complementary base pairing ________.

A) promoter region
B) terminator
C) coding strand
D) template strand

Question 13

Which of the following matching of terms is incorrect?

A) Genome/all the genetic information in an organism.
B) Translation/ribosomes translate the genetic code found in rRNA.
C) Genes/units of heredity that code for production of either RNA or protein.
D) Transcription/RNA polymerase synthesizes RNA from a DNA template.

Question 14

The DNA sequence for enzymes that bind RNA polymerase to DNA, separate strands of DNA and select template strand ________.

A) promoter
B) terminator
C) coding strand
D) template strand

Question 15

The DNA strand not used as template ________.

A) promoter
B) coding strand
C) template strand
D) terminator

Question 16

The key enzyme in the complex that directs building of mRNA transcript ________.

A) RNA polymerase
B) DNA polymerase I
C) RNA primase
D) RNA ligase

Question 17

The terminator sequence is the ________.

A) binding site for enzymes that bind RNA polymerase to DNA, separate strands of DNA and select template strand
B) RNA sequence that binds factors to stop translation and release newly formed mRNA complex
C) RNA sequence that binds factors to stop transcription and release newly formed mRNA complex
D) DNA sequence that binds factors to stop transcription and release newly formed mRNA complex

Question 18

A structural component of ribosomes ________.

A) mRNA
B) tRNA
C) rRNA
D) miRNA

Question 19

________ participates in various regulatory functions.

A) mRNA
B) tRNA
C) rRNA
D) miRNA

Question 20

mRNA ________.

A) is transcribed from DNA template strand, coding molecules are transcribed into proteins
B) participates in various regulatory functions
C) is a structural components of ribosomes
D) is involved in translation by carrying amino acids to ribosomes

Question 21

tRNA ________.

A) is a sequence of ribonucleotides that carries codons that are transcribed into a protein
B) participates in various regulatory functions
C) is structural components of ribosomes
D) is involved in translation by carrying amino acids to ribosomes

Question 22

What description about mRNA is correct?

A) Bacterial mRNAs vary in size but usually have about 1000 nucleotides that code for proteins with 300 amino acids.
B) Bacterial mRNA is longer and more modified than that found in Eukaryotes.
C) Before leaving the nucleus, Prokaryote mRNA has to be capped, spliced and had poly (A) tails added.
D) Both Prokaryotic and Eukaryotic mRNA carry a sequence of anticodons that code for the sequence of amino acids found in proteins.

Question 23

Major characteristics of the tRNA molecules include ________. (Select all that apply)

A) they are smaller than mRNAs ranging from about 70 to 100 nucleotides in length
B) a common basic secondary and tertiary structure
C) while one end of the tRNA temporarily binds a specific amino acid, the other end has the codon that temporarily binds to the anticodon on the mRNA via complementary base pairing
D) the tRNA is the bridge between the nucleotide language of the mRNA and the amino acid language of the developing protein

Question 24

The genetic code ________. (Select all that apply)

A) is contained in codon sequences found in DNA
B) is redundant because there is often more than one choice of codon for each amino acid
C) uses AUG coding for Methionine as the start of every protein
D) uses one of three codons that do not code for an amino acid to stand for "stop" at the end of the protein

Question 25

Which of the following pertain to the transcription part of protein synthesis ________. (Select all that apply)

A) occurs on a ribosome in the cytoplasm
B) occurs before translation
C) requires RNA polymerase
D) requires a template DNA strand

Question 26

The A site on the ribosome ________.

A) peptidyl-tRNA is parked before it transfers its peptide to an aminoacyl-tRNA
B) a tRNA without an amino acid attached exits the ribosome
C) aminoacyl-tRNA binds to the ribosome
D) mRNA attaches to the ribosome

Question 27

The P site on the ribosome is where ________.

A) peptidyl-tRNA is parked before it transfers its peptide to an aminoacyl-tRNA
B) a tRNA without an amino acid attached exits the ribosome
C) aminoacyl-tRNA binds to the ribosome
D) mRNA attaches to the ribosome

Question 28

The E site on the ribosome is where ________.

A) peptidyl-tRNA is parked before it transfers its peptide to an aminoacyl-tRNA
B) a tRNA without an amino acid attached exits the ribosome
C) aminoacyl-tRNA binds to the ribosome
D) mRNA attaches to the ribosome

Question 29

What is the correct order of events that occur during the elongation stage of translation?
1) the appropriate aminoacyl-tRNA with complementary anticodon fills the A site
2) the growing peptide on the peptidyl-tRNA in the P site is transferred to an aminoacyl-tRNA to make a peptide that is now one amino acid longer
3) translocation occurs in which the mRNA slides along the ribosome one codon in the 5' direction.

A) 1,2,3
B) 1,3,2
C) 3,1,2
D) 2,1,3

Question 30

What initiates the termination of the translation process?

A) When a stop codon on the mRNA enters the A site.
B) When a stop codon on the mRNA enters the P site.
C) When a stop codon on the mRNA enters the E site.
D) When a release factor binds to the peptidyl-tRNA causing its dissociation from the ribosome.

Question 31

In the illustration below, the item marked x is ________.

A) the coding strand of DNA
B) the template strand of DNA
C) an Okazaki fragment of DNA
D) the protein coding region of a gene

Question 32

In the illustration below, the item marked v is ________.

A) the coding strand of DNA
B) the template strand of DNA
C) an Okazaki fragment of DNA
D) the protein coding region of a gene

Question 33

The codon sequence 5'-UGG-3' found within the protein-coding region of an mRNA codes for ________.

A) the anticodon 5'-UGG-3'
B) the anticodon 3'-UGG-5
C) the amino acid trp
D) The amino acid gly

Question 34

What step of the elongation of protein synthesis preceded the illustration shown?

A) Aminoacyl-tRNA selection
B) Translocation
C) Peptide transfer
D) Removal of an unacylated tRNA from the E site

Question 35

What stage of the elongation of protein synthesis is shown in the illustration?

A) Aminoacyl-tRNA selection
B) Translocation
C) Peptide transfer
D) Removal of an unacylated tRNA from the E site

Question 36

What step of the elongation of protein synthesis preceded the illustration shown?

A) Aminoacyl-tRNA selection
B) Translocation
C) Peptide transfer
D) Removal of an unacylated tRNA from the E site

Question 37

In the illustration below, what structure is labeled z?

A) An aminoacyl-tRNA
B) A peptidyl-tRNA
C) A tRNA
D) An rRNA

Question 38

Which statement best defines a mutation?

A) A mutation is a change in the amino acid sequence of a gene.
B) A mutation is a change in the amino acid sequence of a protein.
C) A mutation is a change in the nucleotide sequence of a gene.
D) A mutation is a change in the nucleotide sequence of DNA.

Question 39

Spontaneous mutations ________. (Select all that apply)

A) are errors that are induced during DNA replication
B) are inevitable because DNA replication must balance accuracy and the speed of replication
C) occur at a rate of 10^-9 to 10^-9 errors per base pair synthesized
D) are usually corrected because of DNA proofreading

Question 40

Induced mutations can occur as a result of ________. (Select all that apply)

A) chemicals that alter the structure of purines or pyrimidines so they no longer form complementary base pairs
B) nonionizing radiation causing formation of adenine dimers
C) chemicals that add a functional group to nucleotides that distort their structure and cause errors during replication or repair
D) ionizing radiation damaging DNA by creating reactive ions that chemically alter nucleotides

Question 41

Pesticides on foods, tobacco smoke and diesel engine exhaust ________.

A) polyaromatic hydrocarbons
B) nitrosamines/nitrosamides
C) aromatic amines
D) formaldehyde

Question 42

Embalming fluids and volatile gases from paints, floor finishes and cigarette smoke ________.

A) polyaromatic hydrocarbons
B) nitrosamines/nitrosamides
C) aromatic amines
D) formaldehyde

Question 43

Polyaromatic hydrocarbons ________.

A) pesticides on foods, tobacco smoke and diesel engine exhaust
B) carbon-containing fuels, cigarette smoke, and meat cooked at high temperatures
C) embalming fluids and volatile gases from paints, floor finishes and cigarette smoke
D) by-products from manufacture of some cosmetics, pesticides and most rubber products

Question 44

Nitrosamines/nitrosamides ________.

A) pesticides on foods, tobacco smoke and diesel engine exhaust
B) carbon-containing fuels, cigarette smoke, meat cooked at high temperatures
C) embalming fluids and volatile gases from paints, floor finishes and cigarette smoke
D) by-products from manufacture of some cosmetics, pesticides and most rubber products

Question 45

A point mutation can be a ________. (Select all that apply)

A) silent mutation resulting in no effect on protein structure
B) missense mutation resulting in a change in one amino acid in a protein
C) nonsense mutation that results in an amino-acid coding codon changed to a termination codon
D) frameshift mutation caused by addition or deletion of a base pair that results in a shift in the reading frame of the mRNA causing a change in all amino acids occurring after the frameshift

Question 46

Which enzyme directly repairs pyrimidine dimers?

A) Photolyase
B) DNA ligase
C) Endonuclease
D) DNA polymerase I

Question 47

Which statements are true about the nucleotide excision repair process? (Select all that apply)

A) Endonuclease cuts the DNA backbone then removes a short sequence of nucleotides the contains the error.
B) DNA polymerase I incorporates nucleotides to fill a gap in the DNA sequence.
C) DNA ligase connects the repaired piece of DNA to the original strand.
D) Pyrimidine dimer is repaired by photolyase.

Question 48

Which of the following describes the Ames Test? (Select all that apply)

A) It measures the mutagenic potential of achemical compounds.
B) It provides an initial screen for potential carcinogens.
C) Uses a strain of Salmonella typhimurium that cannot make the amino acid Methionine.
D) The potential mutagen is mixed with a pancreatic extract.

Question 49

The Ames Test is a procedure that ________.

A) tests the capability of a mutagen to produce reversion mutations
B) assesses the ability of methionine-requiring strains
C) analyzes the mutagenic ability of E. coli
D) screens for the presence of methionine

Question 50

In the Ames test, which result will indicate that the substance being tested is a potential carcinogen?

A) Appearance of a few spontaneous His⁺ reversion mutants on the control and experimental plates.
B) Appearance of abundant His⁺ reversion mutants surrounding the filter disk on the experimental plate relative to the control plate.
C) Appearance of no spontaneous His⁺ reversion mutants on the control plate.
D) Appearance of abundant His⁺ reversion mutants surrounding the filter disk on the control plate relative to the experimental plate.

Question 51

Horizontal gene transfer means that ________.

A) new genetic material is produced by sexual reproduction
B) bacteria can acquire genes from other bacteria
C) bacteria can transfer new genes via mitosis
D) bacteria can transfer new genes via meiosis

Question 52

Conjugation is ________.

A) genes transferred from bacterium to bacterium via bacteriophage
B) movement and insertion of DNA segments to new positions within chromosome or plasmid
C) naked DNA from the environment is taken up by a bacterium
D) formation of a sex pilus allows transfer of a portion of chromosome or plasmid

Question 53

Transformation is ________.

A) genes transferred from bacterium to bacterium via a bacteriophage
B) movement and insertion of DNA segments to new positions within chromosome or plasmid
C) naked DNA from the environment is taken up by a bacterium
D) formation of a sex pilus allows transfer of a portion of chromosome or plasmid

Question 54

Which of the following is the most frequently used method of horizontal gene transfer used by bacteria?

A) Transformation
B) Transduction
C) Conjugation
D) Transposons

Question 55

What type of bacteria uses conjugation most frequently?

A) Gram-negative bacteria in the gastrointestinal tract.
B) Gram-positive bacteria on the skin and mucous membranes.
C) Acid-fast bacteria in the respiratory system.
D) Endospore-forming bacteria in the gastrointestinal tract.

Question 56

Movement and insertion of DNA segments to new positions within chromosome or plasmid ________.

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

Question 57

________ is (are) produced by ________ when a DNA sequence containing insertion sequences is inserted into a new location causing inactivation of a gene or a change in gene regulation.

A) Spontaneous mutations; transformation
B) Induced mutations; transduction
C) Polygenic variation; transposition
D) Genetic variation; transposition

Question 58

What process is shown in the illustration?

A) Nucleotide excision repair of a thymine dimer.
B) DNA replication.
C) Photolyase repair of a thymine dimer.
D) DNA polymerase I repair of a thymine dimer.

Question 59

What process is shown in the illustration?

A) Nucleotide excision repair of a thymine dimer.
B) DNA replication.
C) Photolyase repair of a thymine dimer.
D) DNA polymerase I repair of a thymine dimer.

Question 60

What structure is labeled z in the illustration?

A) DNA polymerase I
B) DNA ligase
C) Photolyase
D) Endonuclease

Question 61

What structure is labeled x in the illustration?

A) DNA polymerase I
B) DNA ligase
C) Photolyase
D) Endonuclease

Question 62

What structure is labeled z in the illustration?

A) DNA polymerase I
B) DNA ligase
C) Photolyase
D) Endonuclease

Question 63

What is the function of the structure labeled y in the illustration?

A) Remove a short section of DNA containing a thymine dimer.
B) Replace nucleotides in a gap in the DNA sequence.
C) Link together a nick in the sugar-phosphate backbone.
D) Synthesize DNA on the leading strand during DNA replication.

Question 64

What structure is labeled y in the illustration?

A) DNA polymerase I
B) DNA ligase
C) Photolyase
D) Endonuclease

Question 65

The bacterial colonies marked x are ________.

A) colonies of spontaneous his⁺ revertants
B) colonies of mutagen-induced his⁺ revertants
C) his^- colonies which grew on the small amount of histidine add to the plate
D) his⁺ colonies of E. coli

Question 66

The bacterial colonies marked z are ________.

A) colonies of spontaneous his⁺ revertants
B) colonies of mutagen-induced his⁺ revertants
C) his^- colonies which grew on the small amount of histidine add to the plate
D) his⁺ colonies of E. coli

Question 67

The illustration shows the process of ________.

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

Question 68

The illustration shows the process of ________.

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

Question 69

The illustration shows the process of ________.

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

Question 70

When does most of the regulation of gene expression occur in bacteria?

A) During termination of transcription.
B) After termination of transcription.
C) During initiation of transcription.
D) During elongation of transcription.

Question 71

Which of the following statements are true about gene regulation in bacteria? (Select all that apply)

A) Repressor proteins control genes by binding to operator sequences.
B) Proteins the inhibit gene expression are called repressors.
C) Inducer proteins bind to regulatory sequences and enhance transcription.
D) Operons are used to coordinate the expression of structural genes that are needed for the same metabolic pathway.

Question 72

Which of the following best describes how the lac operon in E. coli works? (Select all that apply)

A) The lac operon controls the expression of enzymes needed to transport lactose into the cell and break it down into glucose and galactose.
B) When no lactose is present the repressor blocks transcription of structural genes that code for enzymes that split apart lactose into simple sugars.
C) When lactose is present the repressor is activated thereby permitting the production of enzymes that break up lactose.
D) When the repressor is active, it binds to the promotor sequence which blocks binding of RNA polymerase to the operator sequence.

Question 73

Gene regulation in Eukaryotes include(s) ________. (Select all that apply)

A) packaging of DNA into tight coils around the histone proteins to activate transcription
B) degrading mRNA
C) processing proteins to an active form by cleavage
D) removal of introns and splicing together of exons

Question 74

Which statement is correct concerning the illustration below? (Select all that apply)

A) The repressor protein is active.
B) The repressor protein binds with high affinity to the operator sequence.
C) Transcription of the structural genes is inhibited.
D) The inactive repressor protein binds to the promotor sequence and inhibits transcription of the structural genes.

Question 75

Which statement is correct concerning the illustration below? (Select all that apply)

A) The repressor protein is inactivated by binding to lactose.
B) The repressor protein binds with high affinity to the promoter sequence.
C) Transcription of the structural genes is not inhibited.
D) The inactive repressor protein binds to the promotor sequence allowing RNA polymerase to transcribe the structural genes.

Question 76

What is the function of the item marked z in the illustration?

A) Transport of lactose into the cell.
B) Hydrolysis of lactose to galactose and glucose.
C) Regulation of the regulatory gene.
D) Transcription of the structural genes.

Question 77

What is the function of the item marked y in the illustration?

A) Inactivation of the repressor protein.
B) Hydrolysis of lactose to galactose and glucose.
C) Activation of the repressor protein.
D) Transcription of the structural genes.

Question 78

What is the structure marked x in the illustration?

A) Beta-galactosidase
B) Repressor protein
C) Activator protein
D) Lactose

Question 79

Restriction enzymes ________. (Select all that apply)

A) are used to cut DNA at specific nucleotide sequences
B) DNA sequences where restriction enzyme cut are often palindromic
C) only cut DNA at one site on a chromosome or plasmid
D) often cut the DNA strand asymmetrically so that short single-stranded sticky ends are formed

Question 80

A sequence recognized by DNA replication machinery to facilitate replication within the host cell.

A) Promoter sequence
B) Operator sequence
C) Origin sequence
D) Intron