Deck 2: Bacterial Genetics, metabolism, and Structure

Question 1

Pieces of DNA that move from plasmid to chromosome or vice versa but are not found as separate entities are called:

A)DNA polymerases.
B)transposable elements.
C)plasmids.
D)chromatoids.

Answer 1

B
Plasmids can be separate entities,but transposable elements cannot.

Question 2

The pathway of metabolism that involves a series of electron transfers from reduced carrier molecules such as NADH₂ and NADPH₂ to a terminal electron acceptor is:

A)substrate-level phosphorylation.
B)fermentative metabolism.
C)oxidative phosphorylation.
D)aerobic respiration.

Answer 2

C
Fermentative metabolism is one form of substrate-level phosphorylation.Oxidative phosphorylation is an electron transport system that can use either oxygen as the terminal electron acceptor (aerobic respiration)or acceptors other than oxygen (anaerobic respiration).

Question 3

Mutation is defined as the:

A)change of the bacterial genotypes through the exchange of DNA from one cell to another.
B)internal change in the original nucleotide sequence of a gene or genes within an organism's genome.
C)process by which genetic elements such as plasmids and transposons excise from one genomic location and insert into another.
D)uptake of free DNA from the environment and recombination with the recipient's homologous DNA.

Answer 3

B
Mutation occurs as an internal change in the original nucleotide sequence of a gene or genes within an organism's genome.

Question 4

Recombination is defined as the:

A)change of the bacterial genotypes through the exchange of DNA from one cell to another.
B)internal change in the original nucleotide sequence of a gene or genes within an organism's genome.
C)process by which genetic elements such as plasmids and transposons excise from one genomic location and insert into another.
D)uptake of free DNA from the environment and recombination with the recipient's homologous DNA.

Question 5

In gene regulation and control,repression is defined as the:

A)internal change in the original nucleotide sequence of a gene or genes within an organism's genome.
B)mechanism of genetic control in which genes are induced only when the substrate to be degraded by enzymatic action is present.
C)change of the bacterial genotypes through the exchange of DNA from one cell to another.
D)mechanism of genetic control in which genes are not transcribed and therefore are not expressed in the presence of those target products in sufficient supply.

Question 6

Teichoic acids are:

A)waxy substances that are found in some bacterial cell walls that make the cells resistant to toxic substances,including acids.
B)glycerol- or ribitol-phosphate polymers that are combined with various sugars,amino acids,and amino sugars,which are a part of the cell wall of gram-positive bacteria.
C)high-molecular-weight polysaccharides that coat some bacterial cells and protect the bacteria from attack by cells of the human defense system.
D)hairlike,proteinaceous structures that extend from the cell.

Question 7

The enzyme that adds nucleotide bases to each growing daughter strand in the replication process is called:

A)replication enzymes.
B)DNA polymerase.
C)insertion sequence enzymes.
D)transcriptase.

Question 8

The major difference between gram-positive and gram-negative bacteria is that:

A)the peptidoglycan layer in gram-positive bacteria is substantially thinner than in gram-negative bacteria.
B)gram-positive bacteria contain a periplasmic space,whereas gram-negative bacteria do not.
C)flagella are only present in gram-positive bacteria.
D)gram-negative bacteria contain an outer membrane that functions as the cell's initial barrier to the environment.

Question 9

The mechanism for adenosine triphosphate (ATP)production in which high-energy phosphate bonds produced by the central metabolic pathways are donated to adenosine diphosphate (ADP)to form ATP is:

A)substrate-level phosphorylation.
B)fermentative metabolism.
C)oxidative phosphorylation.
D)aerobic respiration.

Question 10

If a bacterial cell encounters unfavorable environmental conditions,then its metabolism will begin to slow until it eventually transforms into an inactive,dormant state.This survival mechanism is known as:

A)polymerization.
B)oxidation.
C)respiration.
D)sporulation.

Question 11

A pathway that generates ATP by substrate-level phosphorylation that does not require oxygen and produces various end products,including alcohols,acids,carbon dioxide,and hydrogen,is:

A)substrate-level phosphorylation.
B)fermentative metabolism.
C)oxidative phosphorylation.
D)aerobic respiration.

Question 12

Transformation is defined as the:

A)change of the bacterial genotypes through the exchange of DNA from one cell to another.
B)internal change in the original nucleotide sequence of a gene or genes within an organism's genome.
C)process by which genetic elements such as plasmids and transposons excise from one genomic location and insert into another.
D)uptake of free DNA from the environment and recombination with the recipient's homologous DNA.

Question 13

Which organelle is found in eukaryotic cells and is responsible for controlled enzymatic degradation of intracellular substances?

A)Mitochondria
B)Lysosomes
C)Endoplasmic reticulum
D)Golgi body

Question 14

Teichoic acids,mycolic acids,peptidoglycan,and disaccharide-pentapeptide subunits are all building blocks of which bacterial structure?

A)Outer cell membrane
B)Flagella
C)Inner cell membrane
D)Cell wall

Question 15

A DNA sequence that encodes for a specific product (ribonucleic acid [RNA] or protein)is defined as a:

A)gene.
B)genome.
C)nucleotide.
D)deoxyribonucleic acid.

Question 16

Pieces of deoxyribonucleic acid (DNA)that move from one genetic element to another and contain genes for movement and genes for other features are called:

A)transposons.
B)insertion sequences.
C)plasmids.
D)chromatoids.

Question 17

Miniature chromosomes composed of several genes in double-stranded,closed,circular structures are called:

A)transposons.
B)insertion sequences.
C)plasmids.
D)chromatoids.

Question 18

Transduction is defined as the:

A)change of the bacterial genotypes through the exchange of DNA from one cell to another.
B)internal change in the original nucleotide sequence of a gene or genes within an organism's genome.
C)process by which genetic elements such as plasmids and transposons excise from one genomic location and insert into another.
D)mechanism that is mediated by viruses,by which DNA from two bacteria may come together in one cell,thus allowing for recombination.

Question 19

In gene regulation and control,induction can be defined as the:

A)mechanism of genetic control in which genes are induced only when the substrate to be degraded by enzymatic action is present.
B)uptake of free DNA from the environment and recombination with the recipient's homologous DNA.
C)mechanism of genetic control in which genes are not transcribed and therefore are not expressed in the presence of those target products in sufficient supply.
D)change of the bacterial genotypes through the exchange of DNA from one cell to another.

Question 20

The term used when oxidative phosphorylation uses oxygen as the terminal electron acceptor is:

A)substrate-level phosphorylation.
B)fermentative metabolism.
C)anaerobic respiration.
D)aerobic respiration.

Question 21

A patient is infected with a bacteria that is resistant to erythromycin (the antibiotic is not effective)and sensitive to clindamycin (the antibiotic is effective).However,the patient is not improving and the organism now appears to be resistant to both antibiotics.The reason for this alteration in gene expression in the bacterium is likely due to:

A)genetic regulation that encodes the resistance mechanism is constitutive.
B)the genetic regulation encoding the enhanced resistance is inducible.
C)the genetic regulation for the enhanced resistance is normally suppressed.
D)the organism was always resistant to both antibiotics and should not have been treated with the combination therapy.

Question 22

Which of the following processes takes place in the cytoplasm and involves the transfer RNA (tRNA)mediating the sequential addition of amino acids in a specific sequence that is dictated by the codon sequence of the messenger RNA (mRNA)molecule?

A)Transcription
B)Initiation
C)Elongation
D)Termination

Question 23

Amino acids,fatty acids,sugars,and nucleotides are produced during which metabolic reaction?

A)Fueling
B)Biosynthesis
C)Polymerization
D)Assembly

Question 24

All genes within an organism make up that organism's:

A)chromosomes.
B)genome.
C)nucleotides.
D)DNA.

Question 25

A bacterial cell that contains teichoic acid stains which color on the Gram stain?

A)Pink
B)Red
C)Green
D)Purple

Question 26

Neisseria gonorrhoeae are present in the vaginal compartment with nonpathogenic commensal Neisseria spp.When the patient's system begins to attack the pathogenic species,some of the cells autolyze releasing their genetic material into the environment.Other Neisseria species are then capable of taking up the DNA from the organisms that have autolyzed altering their genetic makeup and changing their pili protein structure.This process can be described as:

A)competent cells being transformed by genetic recombination.
B)bacteria ingesting DNA and using the information for transcription.
C)mutation of the pathogenic organisms resulting in enhanced infection.
D)transformation and genetic recombination resulting in expression of new pili proteins to evade the immune system.

Question 27

The structure of bacterial chromosomes differs from that of eukaryotic organisms in all of the following except:

A)bacterial chromosomes are typically circular.
B)the genes are polycistronic.
C)the bacteria have two copies of each chromosome.
D)bacterial mutations are easily transmitted or inherited.

Question 28

A bacterial cell that contains an outer membrane and periplasmic space stains pink to red on Gram stain.Which one of the following statements explains this discrepancy?

A)The bacteria were subjected to too much alcohol during the decolorization process,causing the organism to absorb the pink-to-red dye.
B)The bacteria with an outer membrane and periplasmic space should not be Gram stained because of their cell wall content.
C)Something is wrong with the lot of stains and may be expired.The Gram stain reagents are most likely expired.
D)No discrepancy is present;organisms that contain an outer membrane and periplasmic space should stain pink because of their cell wall composition.

Question 29

In the following genetic sequence,identify the correct complementary strand of DNA for the sequence 3' CAGTACCGTAAGCT 5'

A)3' GTCATGGCATTCGA 5'
B)5' GTCATGGCATTCGA 3'
C)5' AGCTTACGGTACTG 3'
D)5' GTCATGGCTTCGA 3'