Ch.8: Genetics

The genetic makeup of an organism is referred to as its ________, whereas the observable traits are referred to as its ________.

Multiple Choice
genotype; phenotype
chromosomes; gentoype
phenotype; traits
phenotype; genotype

genotype; phenotype

big circle

eukaryote

pill

bacteria

rainbow circle

plasmid

The enzyme that unwinds a segment of the DNA molecule is ________.

Multiple Choice
DNA polymerase
DNA ligase
helicase
RNA primase
DNA polymerase III

helicase

The enzyme that travels along the leading strand assembling new nucleotides on a growing new strand of DNA is ________.

Multiple Choice
DNA polymerase III
DNA ligase
RNA primase
DNA polymerase I
helicase

DNA polymerase III

Before the lagging strand can begin assembling new DNA nucleotides, which of the following must occur?
Multiple Choice
DNA polymerase III adds deoxyribonucleotides.

DNA polymerase I removes some material and replaces it with DNA.

OH bonds must be broken between the two strands of DNA.

DNA ligase forms a phosphodiester bond between the 3' OH of the growing strand and the 5' phosphate in front of it.

RNA primase constructs a short RNA primer.

RNA primase constructs a short RNA primer.

During DNA replication, the lagging strand is synthesized continuously, while the leading strand is synthesized discontinuously.
True or False

False

Before DNA replication can occur, the OH bonds between the strands must be broken.
True or False

False

RNA is a chain of _______.

nucleotides
amino acids
protein
smonosaccharides

nucleotides
Question 1: Both RNA and DNA are composed of chains of nucleotides.

What three components make up RNA structure?

Adenosine, two phosphates
Phosphate, nitrogenous base, ribose sugar
Amino acid, phosphate, nitrogenous base
Phosphate, nitrogenous base, deoxyribose sugar

Phosphate, nitrogenous base, ribose sugar
Question 2: Each nucleotide is composed of a phosphate group, nitrogenous base (AUCG), and ribose sugar.

What component of RNA is different from one individual (or one bacterium) to the next?

Order of nitrogenous bases
Bond between phosphate and sugar
Type of pentose sugar
Number of phosphates

Order of nitrogenous bases
Question 3: As in DNA, the sequence of the bases is what makes each segment unique.

The purpose of RNA synthesis is to provide a new copy of DNA as the original strand deteriorates over time.
TRUE OR FALSE

Question 4: False, DNA is a permanent copy of the genome that exists in the nucleus of eukaryotes or the nucleoid region of prokaryotes. RNA is a temporary copy that can be used to synthesize proteins from the original "blueprint" in the DNA.

Transcription begins when RNA polymerase binds to the ________.

initiator on DNA
terminator on DNA
promoter on DNA
promoter on RNA

promoter on DNA
Question 1: When the RNA polymerase binds to a region on DNA called the promoter, transcription begins.

If one strand of DNA contains the bases ACAGT, what would be the complementary bases on the mRNA strand?

TGTCA
ACAGT
GUGAC
UGUCA

UGUCA
Question 2: The pairing rules are: adenine (A) pairs with uracil (U) and guanine (G) pairs with cytosine (C). There is no thymine (T) in RNA.

Synthesis of mRNA is _______.

-in the 3' to 5' direction with new nucleotides being added to the 5' end of the mRNA molecule
-in the 5' to 3' direction with new nucleotides being added to the 5' end of the mRNA molecule
-in the 3' to 5' direction with new nucleotides being added to the 3' end of the mRNA molecule
-in the 5' to 3' direction with new nucleotides being added to the 3' end of the mRNA molecule

in the 5' to 3' direction with new nucleotides being added to the 3' end of the mRNA molecule
Question 3: Synthesis of mRNA is in the 5' to 3' direction with new nucleotides being added to the 3' end of the mRNA molecule.

What happens when a hairpin loop forms in mRNA?

Exons are removed from the RNA transcript
Transcription of the coding strand begins
Transcription of DNA to mRNA begins
The RNA polymerase and the mRNA dissociate from the DNA

The RNA polymerase and the mRNA dissociate from the DNA

Question 4: When a hairpin loop forms in mRNA, the RNA polymerase and the mRNA dissociate from the DNA.

The process of transcription is similar to ________.

the synthesis of the leading strand during DNA replication translation
the synthesis of the lagging strand during DNA replication
binary fission in prokaryotes

the synthesis of the leading strand during DNA replication translation
Question 1: The process of transcription is similar to the synthesis of the leading strand during DNA replication because it happens as a continuous strand.

After mRNA is made, what generally occurs ________.

it is translated to DNA
it is transcribed again
it is degraded
the mRNA is translated to protein

the mRNA is translated to protein
Question 2: Messenger RNA is generally translated to protein on ribosomes.

Unlike DNA, RNA is usually single stranded
true or false

true

Question 3: Generally, RNA is a single strand of ribonucleotides, whereas DNA is generally double stranded.

A segment of DNA encoding a protein or an RNA molecule is a ________.

genotype
chromosome
phenotype
gene

gene
Question 1: Genes are segments of DNA that contain the information to make a protein or RNA molecule.

. A ________ is the physical expression of the genes present and can change depending upon what genes are turned "on."
plasmid
genotype
phenotype
chromosome

phenotype
Question 2: The physical expression of the genes present is referred to as the phenotype.

Which nitrogenous base is NOT present in RNA?

Cytosine
Uracil
Thymine
Guanine
Adenine

Thymine
Question 3: Thymine is present in DNA, but not in RNA.

Both DNA and RNA are usually double-stranded molecules.
true or false

FALSE

Question 4: Except in the case of some viruses, DNA is double stranded and RNA is single stranded.

The process of synthesizing RNA from a DNA template is ________.

transcription
conjugation
translation
replication

transcription
Question 1: The process of synthesizing RNA from a DNA template is transcription, and the "reading" of the RNA to build the proper amino acid sequence is called translation.

he initial transfer RNA occupies the ________ site on the ribosome.

P site
A site
E site

P site
Question 2: The initial transfer RNA occupies the P site on the ribosome. New incoming tRNAs enter the A site, and the tRNA that has already delivered its amino acid exits from the E site.

_______ are groups of three bases in mRNA that specify one amino acid in the amino acid chain.

Genes
Codons
Anticodons
Triplets

Codons
Question 3: The codons in mRNA contain the code for the order of amino acids in a protein. Anticodons and triplets are also a set of three bases, but they are a part of tRNA and DNA, respectively.

If the codon GGU is positioned in the A site of the ribosome, which of the following will occur?

A tRNA with the anticodon CCA will deliver its amino acid to the site.
The ribosomal complex will dissociate and release the peptide chain.
A tRNA with the anticodon CCT will add its amino acid to the peptide chain.
The mRNA will exit the E site to prepare for another incoming amino acid.

A tRNA with the anticodon CCA will deliver its amino acid to the site.
Question 4: The A site is the position in which a new tRNA delivers its amino acid to the site. The codon on the mRNA specifies which tRNA can deliver its amino acid to this site. The anticodon and codon must be complementary, and therefore, a tRNA with the complementary sequence CCA to the mRNA codon of GGU will enter the A site.

What usually terminates the process of translation?

Depleted tRNA supply
Ribosomes degradation with use
Presence of a repeating mRNA sequence
Presence of a stop codon on mRNA

Presence of a stop codon on mRNA
Question 5: The process of translation ends when a stop codon is encountered, and the complex involving the ribosome is broken apart.

The bond connecting amino acids is a ________ bond.

peptide
hydrogen
glycosidic
ionic

peptide
Question 1: The bond connecting amino acids is a type of covalent bond known as a peptide bond.

If you know the sequence of nucleotides in mRNA, you can deduce the DNA sequence it was transcribed from.
TRUE OR FALSE

true
Question 2: Due to the complementary nature of bases, if you know the mRNA sequence, you can deduce the DNA sequence.

Which of the following depicts the most common direction genetic information flows?

RNA → protein → DNA
Protein → DNA → RNA
DNA → RNA → protein
RNA → DNA → protein

DNA → RNA → protein
Question 3: Genetic information flows from DNA to RNA to protein.

Protein synthesis occurs on the ________.

nuclear membraneI
cell membrane
mitochondria
ribosomes

ribosomes
Question 4: Protein synthesis occurs on ribosomes.

Replication, transcription, and translation take place in the bacterial cytoplasm.
true or false

True
Question 5: Bacteria lack a nucleus; therefore, all three processes take place in the cytoplasm.

Bacteria generally have a single chromosome that is ----- in shape and found in the nucleoid region of the cell.

circular

Before the cell undergoes ------, the chromosome must -------- so each daughter cell receives an identical copy of the genome.

binary fission
be replicated

During this process, which proceeds in the ------ direction, one strand is synthesized continuously and is known as the -------- while the other strand, known as the ------- , must be made in fragments.

5'-3', leading strand, lagging strand

All the individual fragments are eventually joined together by --------, an enzyme that can create a covalent bond between adjacent bases.

DNA ligase

An exact copy of the parental strands is made because of the base-pair arrangement in the strands; adenine always pairs with ----- and guanine always pairs with ------- .

thymine,cytosine

The enzyme ------ limits the occurrence of mutations by proofreading for mistakes.

DNA polymerase,

In order to make proteins, the ------- strand of DNA is used during transcription to synthesize a copy of the gene in the form of ---- , which is identical to the coding strand of DNA except ----- replaces ----- .

template, mRNA, uracil, thymine

triangle & rectangle

amino acid

squiggly things under the triangle & rectangle

tRNAs

squiggly line

mRNA transcript

Prokaryotes lack membrane-enclosed organelles.
true or false

true
Question 1: In contrast to eukaryotes, prokaryotes lack membrane-enclosed organelles, such as a nucleus, mitochondria, and endoplasmic reticulum.

Which of the following occur(s) in both prokaryotes as well as eukaryotes?

DNA replication
Transcription
Translation
All of the choices are correct

All of the choices are correct
Question 2: Both prokaryotes and eukaryotes perform all these processes.

The sequence of DNA bases ultimately determines the sequence of amino acids in a polypeptide.
true or false

true

Question 3: The sequence of DNA bases is the "blueprint" for the assembly of amino acids in a polypeptide. Remember that genetic information flows from DNA to RNA to protein.

Translation of mRNA into protein begins before transcription is complete in ________.
prokaryotes or eukaryotes

prokaryotes
Question 1: Translation of mRNA into protein before transcription is complete can only occur in prokaryotes.

In prokaryotes, the mRNA transcript encounters ribosomal parts immediately as it leaves the DNA.
true or false

true
Question 2: As soon as mRNA is made, its translation can begin in prokaryotes.

A(n) ______ is a cluster of genes that perform related functions found in ________.

transposon; prokaryotes
exon; prokaryotes
intron; eukaryotes
operon; prokaryotes

operon; prokaryotes
Question 3: Related genes in prokaryotes are clustered into operons.

Eukaryotic mRNA contains non-coding regions called ________.

exons
transposons
transcriptors
introns

introns
Question 4: Non-coding regions in eukaryotic mRNA are called introns.

Introns are removed and exons are spliced together _______.

after leaving the nucleus
before transcription
before translation
after translation

before translation
Question 5: Eukaryotic mRNA transcripts must be processed by removing the introns before leaving the nucleus and participating in translation.

Eukaryotic mRNA usually specifies multiple proteins.
true or false

false

Question 6: Eukaryotic mRNA usually specifies only a single protein.

Only eukaryotic mRNA is processed prior to translation.
true or false

true
Question 1: Introns are removed from eukaryotic mRNA, and exons are spliced together prior to translation. Prokaryotic mRNA is translated as it is being synthesized.

Translation of eukaryotic mRNA can occur in the nucleus after exons are spliced together.
true or false

false
Question 2: Translation occurs in the cytoplasm.

Translation occurs on ribosomes only in prokaryotes.
true or false

false
Question 3: Translation occurs on ribosomes in both eukaryotes and prokaryotes.

The processes of transcription and translation differ between prokaryotes and eukaryotes in what way?

Prokaryotic mRNA must be processed by removing introns prior to translation
Eukaryotes transcribe DNA in the cytoplasm
Prokaryotes transcribe and translate simultaneously
Eukaryotes translate DNA in the nucleus
Prokaryotes transcribe DNA in the nucleus

Prokaryotes transcribe and translate simultaneously

Question 4: Since they lack a nucleus and mRNA processing is not required, prokaryotes transcribe and translate simultaneously.

order um
a. exons are spliced
b. primary transcript
c. mRNA ready for translation
d. DNA template
e. transcripts processing

D,B,E,A,C

In eukaryotic DNA, there are segments called introns that are not part of the protein's code. These segments must be taken out of the mRNA transcript after transcription. The remaining exons are spliced together and proceed through translation.

teal protein
isoleucine
arginine
threonine

isoleucine

blue protein
isoleucine
arginine
threonine

arginine

red protein
isoleucine
arginine
threonine

threonine

A permanent change in the base sequence of DNA is a(n) ________.

Multiple Choice
anticodon
operon
endonuclease
mutation

mutation

A permanent change in the base sequence of DNA is a mutation. This may be an addition or deletion or substitution of the bases.

Mutations are the primary source of genetic variation that makes evolution possible.
true or false

true
While many mutations are harmful, some are beneficial and adaptive. It is mutation that creates the genetic diversity, and then natural selection will favor those organisms that have beneficial characteristics.

A mutation that changes a codon that specifies an amino acid to a stop codon, resulting in premature termination of polypeptide synthesis.
missense mutation
nonsense mutation
frameshift mutation
silent mutation

nonsense mutation

A mutation that results in a change in a codon such that a different amino acid is specified.
missense mutation
nonsense mutation
frameshift mutation
silent mutation

missense mutation

A mutation that changes one codon to a different codon that specifies the same amino acid, such that there is no change in the resulting polypeptide.
missense mutation
nonsense mutation
frameshift mutation
silent mutation

silent mutation

A mutation resulting from an insertion or deletion of bases that causes a change in the reading frame of the mRNA.
missense mutation
nonsense mutation
frameshift mutation
silent mutation

frameshift mutation

tryosine -> tryosine
missense mutation
nonsense mutation
frameshift mutation
silent mutation

silent mutation

tryosine (polar) -> asparagine (polar)
is missense mutation....
- both AAs hydrophillic
- new AA is hydrophobic
- new AA has a negative charge

missense mutation
- both AAs hydrophillic

tryosine (polar) -> phenylalanine (nonpolar)
is missense mutation....
- both AAs hydrophillic
- new AA is hydrophobic
- new AA has a negative charge

missense mutation
- new AA is hydrophobic

tryosine (polar) -> aspartic acid (acidic)
is missense mutation....
- both AAs hydrophillic
- new AA is hydrophobic
- new AA has a negative charge

missense mutation
- new AA has a negative charge

tryosine -> stop codon
missense mutation
nonsense mutation
frameshift mutation
silent mutation

nonsense mutation

Conjugation
A. requires a pilus
B. transfer of capsule genes
C. commonly transfers drug and metal resistance/toxin production genes
D. live competent cell picks up DNA fragment from environment
E. direct transfer between two living cells
F. bacterial donor & recipient must be from the same species
G. Can be used in the lab to introduce a plasmid to a host bacterial cell
H. requires a bacteriophage
I. May be specialized or generalize

A. requires a pilus
C. commonly transfers drug and metal resistance/toxin production genes
E. direct transfer between two living cells

Transformation
A. requires a pilus
B. transfer of capsule genes
C. commonly transfers drug and metal resistance/toxin production genes
D. live competent cell picks up DNA fragment from environment
E. direct transfer between two living cells
F. bacterial donor & recipient must be from the same species
G. Can be used in the lab to introduce a plasmid to a host bacterial cell
H. requires a bacteriophage
I. May be specialized or generalize

B. transfer of capsule genes
D. live competent cell picks up DNA fragment from environment
G. Can be used in the lab to introduce a plasmid to a host bacterial cell

Transduction
A. requires a pilus
B. transfer of capsule genes
C. commonly transfers drug and metal resistance/toxin production genes
D. live competent cell picks up DNA fragment from environment
E. direct transfer between two living cells
F. bacterial donor & recipient must be from the same species
G. Can be used in the lab to introduce a plasmid to a host bacterial cell
H. requires a bacteriophage
I. May be specialized or generalize

F. bacterial donor & recipient must be from the same species
H. requires a bacteriophage
I. May be specialized or generalize

1. Plasmids are ________.

made of single-stranded DNA
found in all bacteria
small pieces of linear DNA
able to replicate independently of the chromosome

able to replicate independently of the chromosome
Question 1: Plasmids are small, circular pieces of DNA able to replicate independently of the chromosome.

A recombinant organism is ________.

one that has undergone a mutation
one that has no fixed species designation
one that contains genes from another organism
one that has donated genes to another organism

one that contains genes from another organism
Question 2: A recombinant organism is one that contains genes from another organism transferred via conjugation or some other method of horizontal gene transfer.

If you find that a particular plasmid has an R factor, the bacteria that has it will be ________.

protected by a capsule
moving with a rotating axial filament
able to recycle nitrogenous waste into nitrates
resistant to antibiotics

resistant to antibiotics
Question 3: R factors can make bacteria resistant to antibiotics such as penicillins, sulfonamides, or tetracycline.

The main value of bacteria being able to carry out conjugation and other forms of recombination is ________.

they reproduce much more quickly
they can increase the size of their chromosome
they can protect their genetic material from heat, radiation, and chemicals
they create genetic diversity

they create genetic diversity

Question 4: Binary fission is essentially asexual, so these recombination mechanisms help bacteria vary their genetic makeup and respond better to changes in their environment.

. F+ cells ________.

lack a plasmid and are recipients in conjugation
have a plasmid and are donors in conjugation
lack a plasmid and are donors in conjugation
have a plasmid and are recipients in conjugation

have a plasmid and are donors in conjugation
Question 1: F+ cells have a plasmid and are donors in conjugation.

The F pilus is ________.

a projection of the cell's plasma membrane
a protein appendage that attaches the two cells
a polymer of peptidoglycan that binds to the receipent's cell wall
a modified micro filament

a protein appendage that attaches the two cells
Question 2: The F pilus is a protein appendage or tube that attaches the donor and recipient cells.

The F pilus binds to ________.

saccharides on the recipient
specific receptors on the cell wall of the recipient
endocytic vesicles on the recipient plasme membrane
techoic acid in the cell wall of the recipient

specific receptors on the cell wall of the recipient
Question 3: The F pilus binds to specific receptors on the cell wall of the recipient. This specificity means conjugation takes place between members of the same or similar species.

The plasmid is mobilized for transfer when ________.

an endonuclease cleaves it at the origin of replication
it is glycosylated by the Golgi complex
a helicase unwinds the two strands
single-strand stabilizing proteins attach to it

an endonuclease cleaves it at the origin of replication
Question 4: The plasmid is mobilized for transfer when an endonuclease cleaves it at the origin of replication.
IT CUT FREE

Plasmid DNA is transferred ________.

in double-stranded form
in single-stranded form
as an RNA copy
in 100 bp fragment

in single-stranded form

Question 5: Plasmid DNA is transferred in single-stranded form. Each single strand is copied to produce a new double-stranded plasmid in each cell.

The F plasmid encodes for ________.

- an endonuclease that cleaves the - - origin of replication
receptors on the cell surface
- antibiotic resistance
- the F pilus

- the F pilus
Question 1: The F plasmid encodes for the F pilus; therefore, F+ cells can make the pilus and serve as donors in conjugation.

The first step in conjugation is ________.

duplication of the plasmid
mobilization of the plasmid
the release of quorum signalling proteins by each cell
contact between the donor and recipient

contact between the donor and recipient
Question 2: Conjugation depends on contact between the two cells before the other events can take place.

After the transfer of the F plasmid is complete ________.

the F- cell becomes F+
the F+ cell expresses an R factor
the F+ cell becomes F-
the F- cell becomes HfR

the F- cell becomes F+

Question 3: After the transfer of the F plasmid is complete the F- cell becomes F+ because it now contains an F plasmid and can make a pilus.

The classic transformation experiment done by Griffith used ________.

smooth and rough strains of pea plants
Bacillus anthracis
wild-type and mutant strains of E.Coli
harmless and virulent strains of Streptococcus pneumoniae

harmless and virulent strains of Streptococcus pneumoniae
Question 1: The classic transformation experiment done by Griffith used mice and harmless (rough) and virulent (smooth) strains of Streptococcus pneumoniae.

Transformation is a form of recombination. Recombination is ________.

DNA-protein binding
a form of asexual reproduction for bacteria
a form of mutation that occurs in bacteria
one bacterium donating DNA to another

one bacterium donating DNA to another
Question 2: Recombination is one bacterium donating DNA to another in a number of different ways. This can either happen naturally or through genetic engineering techniques.

. In addition to transformation, the other two forms of horizontal gene transfer (or recombination) are ________.

insertion and deletion
conjugation and transduction
missense and nonsense
translation and transduction

conjugation and transduction

Question 3: In addition to transformation, the other two forms of recombination are conjugation ("bacterial sex") and transduction (the transfer of DNA using phage vectors).

In the beginning of transformation, ________ binds to the target cell.

single-stranded DNA
a plasmid
double-stranded DNA
hairpin loop RNA

double-stranded DNA
Question 1: In the beginning of transformation, a fragment of double-stranded DNA binds to the target cell.

During the entry of the donor DNA into the recipient cell, ________.

it enters in double-stranded form
it is converted into RNA, which passes through pores in the plasma membrane
the DNA binds to fimbrace on the cell's surface
one strand is broken down by nucleases

one strand is broken down by nucleases
Question 2: During the entry of the donor DNA into the recipient cell, one strand is broken down by nucleases and the other enters the cell.

The donor DNA ________.

binds to the F factor in the recipient DNA
binds to the origin of replication in the recipient
pairs with a purine-rich region in the recipient DNA
pairs with a homologous region of the recipient DNA

pairs with a homologous region of the recipient DNA
Question 3: The donor DNA pairs with a homologous region of the recipient DNA.

Mismatch repair is activated by ________.

insertion of an DNA into the recipient
any difference between the length of the donor and recipient DNA
binding of DNA to the surface protein
any difference between the nucleotide sequence in the donor and recipient DNAs

any difference between the nucleotide sequence in the donor and recipient DNAs
Question 4: The mismatch repair mechanism is activated by any difference between the nucleotide sequence in the donor and recipient DNAs.

. As a result of mismatch repair during transformation, ________.

cells may have either original DNA or donor DNA in them
the donor DNA will become circularize and extrachromosomal
all cells will have donor DNA in them
all donor DNA will be excised

cells may have either original DNA or donor DNA in them
Question 5: As a result of mismatch repair during transformation, cells may have either original DNA or donor DNA in them after the repair.

During the process of transformation in the lab setting, cells are plated on selective media to ________.

make sure that only transformants grow
prevent the growth of contaminants that arise during the process
stimulate DNA repair enzymes
block the enzymes that might excise the inserted DNA

make sure that only transformants grow
Question 1: During the process of transformation, cells are plated on selective media to make sure that only transformants grow, since only the transformants contain a certain gene needed to survive.

Cells that are capable of bringing DNA from their environment in through their cell wall are called ________.

porous
acceptant
competent
endocytic

competent
Question 2: Cells that are capable of bringing DNA from their environment in through their cell wall are called competent.

Transformation is facilitated by ________.

chemicals such as a cradine dyes
porins in the bacterial cell wall
binding of the donor and recipient cells
proteins on the cell wall that bind DNA from the environment

proteins on the cell wall that bind DNA from the environment

Question 3: Transformation is facilitated by proteins on the cell wall that bind DNA from the environment.

An operon is a group of genes in a linear arrangement that will be transcribed together and require only one _________ to initiate transcription and one _______ to act as an on/off switch.

Multiple Choice
regulator; promoter
promoter; operator
operator; promoter
operator; repressor

promoter; operator
The operon arrangement of genes improves efficiency of regulation because there is only one promoter, which is necessary to initiate transcription of all the genes in the operon and only one operator sequence that acts as an on/off switch for the operon.

Bacteriophage adsorb or attach ________.

nonspecifically to bacterial cell walls
only to members of the same species
only to members of the Eubacteria
only to members of the same family

only to members of the same species
Question 1: Typically, bacteriophage adsorb or attach specifically to one bacterial species. Because of that, transduction occurs between members of the same species.