Allolactose
Glucose
Repressor proteins
Lactose
Galactose
lacY
The operator region
lacZ
The regulatory gene
The promoter region
lacY
The operator region
lacZ
The regulatory gene
The promoter region
the repressor proteins are inactivated.
no transcription of the regulatory genes occurs.
the repressor proteins bind to the operator.
transcription of the structural genes occurs.
To code for enzymes involved in synthesizing lactose.
To produce lactose when none is present
To produce glucose when none is available
To code for enzymes involved in catabolizing lactose.
The promoter
The operator
The repressor protein
The repressor mRNA
DNA is flexible.
DNA is antiparallel.
DNA has a helical shape.
DNA is double-stranded.
They link the leading strand DNA polymerase and the lagging strand DNA polymerase together.
They enable one parental DNA strand and one newly synthesized DNA strand to be held together.
They allow DNA synthesis to occur in the 3′ to 5′ direction.
They produce the Okazaki fragments.
Neither the leading nor the lagging strand is synthesized continuously.
The leading and lagging strands are both synthesized continuously.
Lagging strand
Leading strand
DNA ligase
Discontinuous
Lagging strand
Lagging strand, DNA ligase, and discontinuous
DNA synthesis on the lagging strand occurs 3′ to 5′.
The lagging strand only requires one primer instead of multiple primers.
The lagging strand only produces single-stranded DNA molecules.
The synthesis is moving in the opposite direction from the replication fork.
The terminator region
The promoter
The template DNA
coding strand of DNA.
RNA strand.
template strand of DNA.
stem loop.
terminator sequence.
termination protein.
promoter sequence.
Increase the amount of DNA
Increase the concentration of promoters
Increase the level of transcription
5′ to 3′
Right to left
Left to right
3′ to 5′
A site
P site
E site
The preceding amino acid will not permit it to enter the A site.
The anticodon on the tRNA base pairs to the codon on the mRNA.
The incorrect tRNA does not fit into the A site.
In the A, P, and E sites
In the A and P sites
In the A site
In the P site
In the E site
In the P and E sites
When a protein called a release factor enters and binds to the A site
When the ribosome runs out of the mRNA
When the A, P, and E sites are all filled
When there are no more charged tRNA molecules
One in every million nucleotides replicated.
One in every ten thousand nucleotides replicated.
One in every trillion nucleotides replicated.
One in every billion nucleotides replicated.
nonsense mutation.
missense mutation.
silent mutation.
frameshift mutation.
nonsense mutation.
missense mutation.
silent mutation.
frameshift mutation.
frameshift mutation.
missense mutation.
silent mutation.
nonsense mutation.
One out of every billion mutations
One out of every three mutations
Half of all mutations
One out of every million mutations
Transduction transfers DNA from the chromosome of one cell to another.
The bacteriophage takes fragments of the cell with it during transduction.
The bacteriophage does not erupt from an infected cell during transduction.
Generalized transduction is initiated during lytic cycle of a virulent bacteriophage; specialized transduction is initiated during the lysogenic cycle of a temperate bacteriophage.
Specialized transduction uses animal viruses instead of bacteriophage.
Only one specific host gene is transferred in both specialized transduction and generalized transduction.
Generalized transduction is initiated by a lysogenic bacteriophage; specialized transduction is initiated by a lytic phage.
contains fragments of the host chromosome instead of the viral genome.
is a lysogenic bacteriophage.
has a viral coat made of host proteins.
cannot infect new host cells.
it will cause the new cell to produce more transducing phage.
the DNA from the previous host can recombine with the new host chromosome.
the new host cell will be lysed.
F+ cells have no plasmids.
Hfr strains can no longer reproduce.
Hfr cells cannot perform conjugation.
Hfr strains have the F plasmid integrated into the chromosome.
Hfr strains lack fertility factor.
The cell membranes between the two strands never fuse together.
Conjugation is typically disrupted before the fertility factor can be transferred.
The transferred genes typically recombine with the recipient chromosome
Ability to mate with an F- cell
Presence of a fertility factor
Ability to synthesize sex pili, presence of a fertility factor, and ability to mate with an F- cell.
Ability to synthesize sex pi
It picks up a fertility factor.
It can now produce sex pili.
It acquires new, potentially beneficial genes from the Hfr strain.
It becomes an F+ cell.
oxidative phosphorylation
photophosphorylation
catabolism
substrate-level phosphorylation
to generate energy in the absence of oxygen
to regenerate NAD+ from NADH
to produce ATP
to be an alternative to glycolysis
chemoautotroph
chemoheterotroph
photoheterotroph
photoautotroph
carbon dioxide
glucose
oxygen
pyruvic acid
They bind to the substrate.
They produce products toxic to the enzymes.
They degrade the substrate.
They compete with the substrate for the enzyme’s active site.
Competitive inhibitors have structures that resemble the enzyme’s substrate.
Competitive inhibitors cover the entire surface of an enzyme.
Competitive inhibitors form unique covalent bonds with enzyme structures.
Competitive inhibitors have unique sugars that are attracted to the enzyme.
PABA will not be catalyzed.
Sulfanilamide products will be in higher concentration.
PABA products will increase in concentration.
The substrate will destroy the inhibitor.
The inhibitor will destroy the substrate.
Competitive inhibitors decrease the rate of enzyme activity.
The inhibitor will destroy the enzyme.
The inhibitor will degrade the substrate.
Energy allows only the substrate to bind.
Energy is required to disrupt a substrate’s stable electron configuration.
Energy is needed for the enzyme to find its substrate.
Energy is required by an enzyme so that it can be reused.
Enzymes produce biological organisms.
Enzymes speed up the chemical reactions in living cells.
Enzymes are products of biological systems.
Enzymes produce products useful for biology.
Enzymes increase the energy barrier required of chemical reactions.
Enzymes decrease the amount of activation energy required for chemical reactions to occur.
Enzymes are reuseable.
Enzymes prevent unwanted chemical by-products from forming.
a redox reaction.
an oxidation reaction.
a reduction reaction.
the donor molecule loses an electron and becomes oxidized.
the donor molecule gains an electron and becomes oxidized.
the acceptor molecule gains an electron and becomes oxidized.
the acceptor molecule loses an electron and becomes oxidized.
The number of molecules in the reaction decreases.
The amount of energy in the molecule decreases.
The electron acceptor’s net charge decreases.
The electron acceptor gets smaller.
Redox reactions involve an oxidation reaction coupled with a reduction reaction.
No metabolic reactions are redox reactions.
Redox reactions are only seen in the electron transport chain.
Redox reactions must either be oxidizing reactions or reducing reactions.
magnesium and potassium required as cofactors for enzymes
sulfur used for synthesis of thiamin and biotin
phosphorus used for production of carbohydrates.
phosphorus incorporated into nucleic acids
nitrogen needed for amino acid synthesis
They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.
They cut DNA at sequences that have lots of adenine bases.
They have the ability to cut DNA randomly.
To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene
To insert a desirable gene
To remove an undesirable gene
To replace a defective gene with a working gene
Plasmids
Restriction enzymes
DNA ligase
Chromosomal DNA
Restriction enzymes can only be used inside of a cell.
Plasmids cannot be isolated outside of a host cell.
It can protect the recombinant DNA.
It can be copied, transcribed, and translated into a desired protein.
a cell that is genetically identical to its parent
an identical copy of the gene of interest
a vector, once it contains a copy of the gene of interest
a culture of genetically identical cells
Cells usually won’t copy an isolated gene sequence.
The clone must be able to produce proteins from the rDNA containing the gene of interest.
The vector ensures that the clone remains pure.
The gene of interest must be isolated from adjacent genes.
A clone is generated when a cell takes up the vector.
Producing a clone generates many copies of the gene of interest.
A clone is used to get the gene of interest into a suitable cell.
Recombining the clone produces the recombinant DNA.
PCR creates large amounts of DNA from minute source quantities.
PCR stimulates transcription of genes (DNA).
PCR harvests small quantities of DNA.
PCR separates DNA from crude mixtures of other biomolecules.
To provide a structure from which DNA can be synthesized
To activate DNA polymerase to replicate DNA
To separate double-stranded DNA into single strands
To provide a template for free nucleotides
Adds reagents to facilitate the PCR run
Monitors the synthesis of DNA
Purifies DNA from a crude sample
Subjects samples to temperature changes
from user-provided DNA and primers
after exposure to 94∘C
at 94∘C
at 55∘C
To allow primers to bind to the DNA template strands
To separate the DNA template strands
To optimize DNA polymerase activity
To allow the DNA template strands to bind to each other
DNA polymerase would be active at 94∘C.
Primers would NOT bind to DNA template strands.
DNA template strands would bind to each other.
DNA polymerase would synthesize DNA more slowly.
The denaturation step of each cycle only separates some of the source DNA. By performing numerous cycles, PCR generates copies of all the target sequences.
Each cycle of PCR incorporates some of the included primers into amplicons. Numerous cycles of PCR are required to ensure all primers are incorporated.
Each cycle of PCR doubles the amount of DNA synthesized, but the number of copies starts out small. Numerous cycles are required to produce a sufficient number of copies.
Each cycle of PCR allows Taq polymerase to partially synthesize the target sequence. Numerous cycles are necessary for the target sequence to be fully copied.
Genetically engineered crops have natural characteristics that give them a genetic advantage.
Genetically engineered crops have a genetic advantage because the parent strains have advantageous traits.
Genetically engineered crops have an advantageous gene from another organism inserted into their genome.
Genetically engineered crops naturally produce larger plants and bountiful products.
The Bt toxin will protect the plant from pathogenic bacteria.
The plant will release chemicals that will repel all nearby insects.
People who eat the food produced by a Bt crop will be resistant to bacterial infections.
Insects that normally destroy non-toxin-producing crops will be killed when they eat plants that do produce the toxin.
The bacterial gene for Bt toxin is isolated, and the DNA is put into tiny bullets (like BB’s) that are “shot” into the cotton plant using a gene gun.
The Bt toxin gene is isolated and inserted into a Ti plasmid from Agrobacterium tumefaciens. The engineered Ti plasmid is taken up by a bacterium that infects the cotton plant.
A virus is engineered to contain the Bt toxin gene. This virus is then used to infect the plant and pass on the gene.
The Bt toxin gene is added to water that is sprayed on the cotton plants. The gene is taken up through the roots of the plant.
