Deck 2: Bacterial Genetics, Metabolism, and Structure

Question 1

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.

Answer 1

D
Bacteriophages, viruses that infect bacteria, integrate their DNA into the bacterial cell's chromosome, in which viral DNA replication and expression is directed; thus, the DNA is dispersed to another bacterium when other cells are infected.

Question 2

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.

Answer 2

B
Teichoic acids, mycolic acids, peptidoglycan, and disaccharide-pentapeptide subunits are all building blocks of the bacterial cell wall.

Question 3

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.

Answer 3

D
To avoid waste and overproduction of enzymes in the cell, some genes are turned off by the presence of the product of that gene expression.

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

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

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

Question 6

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 7

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 8

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.

Question 9

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 10

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 11

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 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

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 14

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 15

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.

Question 16

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 17

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 18

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 19

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 20

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.

Question 21

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

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

Question 22

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

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

Question 23

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 24

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 25

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

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