DNA Assignment Reading
Put the following steps in the order that they occur during transcription initiation in eukaryotes, beginning with the first step at the top. Instructions
1. A transcription factor binds to the TATA box of the promoter. 2. The TATA binding protein attracts other transcription factors, including transcription factors bound at enhancers. 3. RNA polymerase is able to bind to the promoter at the start of the gene and begin transcription.
Arrange the events of eukaryotic protein production in the order that they occur, beginning with the first event at the top. Instructions
1. Inside the nucleus, a gene's DNA sequence is transcribed to form a complementary sequence of RNA. 2. The RNA is modified. 3. The RNA moves out of the nucleus and binds to a ribosome. 4. At the ribosome, amino acids are assembled in a specific order to produce a protein.
Arrange the events of transcription in the order that they occur, beginning with the first event at the top.
1. RNA polymerase binds to the gene's promoter. 2. RNA polymerase moves down the template strand, producing a complementary RNA molecule. 3. RNA polymerase separates from the DNA and the newly synthesized RNA is released.
Arrange the events of transcription in the order that they occur, beginning with the first event at the top. Instructions
1. RNA polymerase binds to the gene's promoter. 2. RNA polymerase moves down the template strand, producing a complementary RNA molecule. 3. RNA polymerase separates from the DNA and the newly synthesized RNA is released.
Place these translation initiation and elongation events in order from the first step at the top to the last step at the bottom.
1. The 5' end of the mRNA molecule binds with the small ribosomal subunit. 2 The first tRNA binds to the start codon on the mRNA molecule. 3. The large riobsomal subunit binds to the small ribosomal subunit. 4. The second tRNA molecule binds to the second codon on the mRNA molecule. 5. A covalent bond is formed between the two amino acids. 6. The ribosome releases an empty tRNA.
The average size of an exon is about
100-300 nucleotides.
Given that there are 20 common amino acids in living things, researchers determined that the length of each codon in RNA is
3 nucleotides.
During transcription, RNA polymerase moves along the DNA template strand, adding RNA nucleotides to the growing ______ end of the RNA molecule.
3'
If a DNA sequence underwent a missense mutation, what would be the result?
A codon would code for a different amino acid.
Shortly after transcription in eukaryotic cells, a string of 100-200 adenines is added to the 3' end of the mRNA molecule, producing what is known as a poly _____ tail, and a short sequence of nucleotides called the 5' is added to the 5' ___ end of the mRNA molecule.
A;cap
Select all of the following that are true about the genetic code.
AUG encodes methionine and "start." The same genetic code is used by nearly all species. There are three codons that act as "stop" codons.
During translation initiation, the first codon to specify a particular amino acid is usually ______, which encodes the amino acid ______.
AUG; methionine
Using the table (which is shown larger in the text), select all of the following mRNA sequences that would code for the polypeptide Met-Ser-His-Arg-Gln.
AUGUCUCAUCGUCAA AUGUCCCAUCGUCAA AUGUCUCACCGUCAA AUGUCUCAUCGUCAG
The mRNA sequence ______ codes for the amino acid sequence Met-Trp-Arg.
AUGUGGAGG
Avery, McCarty, and MacLeod
Discovered that DNA was the transforming principle.
If an mRNA was blocked from exiting the nucleus, what would happen to expression of the gene from which the RNA transcript was made?
The gene would be silenced.
What is an example of an expanding repeat mutation?
The number of copies of the sequence CCG increases every time the DNA is copied.
Select all of the following that are true about the termination stage of translation.
The polypeptide is released. A release factor protein prompts the release of the last tRNA from the ribosome. The large and small ribosomal subunits separate.
What would result if a mutation caused the addition of the three-base codon GUG?
The protein product would contain one extra amino acid.
Select all the statements about nucleotides that are accurate.
They are composed of a sugar, a nitrogen-containing group, and one or more phosphorus-containing groups. DNA always contains the same sugar in its nucleotides.
Select all of the following that are true about codons.
They are composed of three mRNA bases. They correspond to one amino acid.
True or false: Although mutations often cause changes that are harmful, they are also the source of genetic variation for evolution.
True
True or false: During the early part of the twentieth century, some biologists believed that proteins were more likely than DNA to be the molecule of heredity.
True
True or false: Unlike DNA, RNA can catalyze chemical reactions.
True
Explain the data shown in the image, as it relates to FOXP2, the "language gene."
Two amino acids have changed in the human FOXP2 protein relative to an ancestor.
In the base pairs of the DNA double helix,
a double-ring base always pairs with a single-ring base.
gene
a sequence of nucleotides that codes for a specific protein or RNA molecule
Bacterial genomes normally consist of ______ chromosome(s), whereas eukaryotic genomes are normally made up of ______ chromosome(s).
a single circular; multiple linear
Two strands of DNA within the double helix are said to be complementary to each other because ____ on one strand always pairs with thymine on the opposite strand, and cytosine on one strand always pairs with ______ on the opposite strand.
adenine;guanine
Most of the epigenetic markers present in a multicellular organism are placed onto its DNA
after the sperm and egg cell unite in fertilization.
Protein processing and degradation is a method of regulating gene expression that occurs
after translation.
The term genome refers to
all the genetic material in an organism's cell.
A variant of a gene is referred to as a(n)
allele.
Mutations can lead to genetic variability because they create new _____ , or variants of genes.
alleles
Select all the types of protein modification that can occur after translation to produce a functional protein.
altering or cutting by enzymes joining with other polypeptides
What gene regulation mechanism allows for the production of different proteins from the same mRNA?
alternative splicing of exons
On a tRNA molecule, the ______ is a three-base sequence that is complementary to and binds to an mRNA codon during translation.
anticodon
What 3-base site of a tRNA molecule is complementary to an mRNA codon?
anticodon
A(n)___ is a three-base sequence on the tRNA that binds to a(n) ____ on the mRNA.
anticodon;codon
Although the two chains of the DNA double helix are parallel to each other, they are oriented in opposite directions. This head-to-tail configuration is referred to as a(n) ______ arrangement.
antiparallel
Select all of the following that describe the nitrogenous bases adenine and guanine.
double-ring structure purines
A(n) ______ is a sequence of DNA nucleotides that codes for a specific protein or RNA molecule.
gene
All of the genetic material that is within a cell is called its
genome.
CUU
leucine
rRNA
major component that makes up the structure of a ribosome
In bacteria, a(n) ______ is a group of genes under control of a single promoter.
operon
A ribosome is composed of
rRNA and proteins.
Only producing proteins that are needed allows a cell to
save energy.
Select all of the following that are genes.
sequence of DNA nucleotides that codes for a specific protein sequence of DNA nucleotides that codes for a specific RNA molecule
AGC
serine
A mutation that causes an mRNA nucleotide to change from GGC to GGA is a ______ mutation.
silent
A substitution mutation is said to be ______ if the mutated gene encodes the same protein as the original gene version.
silent
Select all of the following agents or processes that can cause mutations.
some forms of radiation errors in DNA replication chemical mutagens
Select all of the following that are methods of gene regulation found in eukaryotes but not prokaryotes.
splicing exons in alternative ways adding methyl groups to silence genes blocking mRNA exit from the nucleus
When the ribosome exposes a UGA, UAG, or UAA codon on the mRNA during translation, release factors rather than tRNAs bind to these codons, which is why these three sequences are called _____ codons.
stop
rRNA
structural component of the ribosome
Defects in ______ can affect the production of proteins that regulate cell division and can lead to cancer.
transcription factors
UAC
tyrosine
Select all of the following that occur during the elongation stage of translation.
Bonds between amino acids are formed. Amino acids are transferred from tRNAs to a polypeptide chain. Proteins called elongation factors assist in translation elongation. Anticodons bind to their complementary codons.
In the DNA molecule, why does A pair with T and not C?
Both A and T can only form two hydrogen bonds.
Which scientist showed that the amount of the base guanine in a DNA molecule equals the amount of the base cytosine in a DNA molecule?
Chargaff
A eukaryotic chromosome consists of
DNA wrapped around histones and other proteins.
During transcription, RNA nucleotide bases bind with the exposed complementary bases on the template strand of
DNA.
Hershey and Chase showed that the part of a virus that could enter bacterial cells and cause the production of more viruses was
DNA.
The information that each cell needs to produce proteins is stored in a molecule called
DNA.
Early in the twentieth century, scientists were at first hesitant to accept that ____ was the genetic information molecule because ____ , with its 20 common amino acid building blocks, could code for many more traits.
DNA;protein
Hershey and Chase
Demonstrated that radioactively-labeled DNA, not protein, entered bacterial cells and directed them to produce viruses.
Erwin Chargaff
Determined that DNA contains equal amounts of adenine and thymine and of guanine and cytosine
Griffith
Discovered that one strain of bacteria could "transform" another by inducing it to display new traits.
Garrod
Discovered that people with "inborn errors of metabolism" lacked certain enzymes.
______ are portions of mRNA that get spliced together to form mature mRNA prior to translation.
Exons
True or false: A mutation that occurred in a brain cell due to radiation exposure would be passed to the next generation.
False
True or false: Complementary base pairing rules state that in DNA, A pairs with G and T pairs with C.
False
True or false: In the 1940s, Avery, McCarty, and MacLeod figured out that the "transformation principle" from Griffith's experiments was actually protein.
False
True or false: Since the nineteenth century, scientists have known that DNA is the molecule of heredity.
False
Select all of the following that are true about prokaryotic versus eukaryotic gene expression.
In eukaryotes, the nuclear membrane separates transcription from translation. In eukaryotes, mRNA is altered before it leaves the nucleus.
Select all of the following that are true with respect to genomes.
In eukaryotic cells, the genome is usually divided up into multiple chromosomes. In prokaryotic cells, the genome usually consists of just one circular DNA molecule.
What is one major difference between eukaryotes and prokaryotes with respect to translation?
In prokaryotes, translation can take place even before transcription is complete.
Select all of the correct statements regarding the results of Frederick Griffith's 1928 experiment involving Streptococcus pneumoniae.
Live S strains caused pneumonia in mice. Heat-killed S strains mixed with live R strains caused pneumonia in mice.
____ in DNA may arise spontaneously as errors in replication, or they can be induced by external agents, like chemicals and radiation.
Mutations
Select all of the following that are true regarding mutations.
Mutations can be the causes of diseases. Mutations are alterations in DNA sequences. Some mutations have little to no effect on protein folding.
What occurs in a deletion mutation?
One or more nucleotides are removed from the DNA.
A gene is a sequence of DNA nucleotides that encodes a specific protein or
RNA molecule.
Gene expression is the production of a functional ______ or a ______.
RNA molecule; protein
The modern definition of gene is any stretch of DNA that is transcribed to
RNA or protein.
During transcription, what enzyme attaches to the promoter, unzips the DNA double helix, and adds complementary RNA nucleotides?
RNA polymerase
initiation
RNA polymerase binds to the gene's promoter.
elongation
RNA polymerase moves down the template strand, adding nucleotides and producing a complementary RNA molecule.
termination
RNA polymerase separates from the DNA and the newly synthesized RNA is released.
In transcription, a(n) ______ molecule is produced from the information that is encoded in a(n) ______ molecule.
RNA;DNA
______ mutations do not pass from generation to generation because they occur in non-sex cells.
Somatic
Due to complementary base pairing rules, a sequence of AAGCTA on one strand of the DNA double helix means that the sequence on the opposite strand is
TTCGAT.
Select all the reasons why the polypeptide product of translation may be nonfunctional.
The amino acid sequence of the protein is altered. The polypeptide misfolds or clumps. The DNA sequence is altered due to mutation.
Select all of the effects on the lac operon when the repressor is bound to the operator.
The bacterial cell conserves energy by not producing lactose-degrading enzymes. RNA polymerase is unable to initiate transcription.
Select all of the following that are true about Hershey and Chase's experimental design in 1950.
They used radioactive labels to mark proteins in one set of viruses and to mark DNA in another set of viruses. After infection of the bacteria, they agitated the mixture to separate the viral coats from the bacterial cells. They used bacteriophages to infect bacteria in order to determine whether DNA or protein was the genetic information.
True or false: A mutation that occurs in a sperm cell has the potential of being passed on to the next generation.
True
Maurice Wilkins and Rosalind Franklin
Used X-ray diffraction to determine that DNA has a regular, repeating structure of building blocks
James Watson and Francis Crick
Used the known ratios of nucleotides along with the X-ray diffraction data to build a ball-and-stick model of the DNA double helix
What scientists worked out the double helical structure of DNA using a ball-and-stick model?
Watson and Crick
The ______ pattern generated by Wilkins and Franklin revealed that DNA was comprised of a regular repeating structure of building blocks.
X-ray diffraction
On one half of a DNA double helix, a single strand of nucleotides has
a 3' end on one side, and a 5' end at the opposite end.
Select all of the following that are utilized in the process of translation.
amino acids ribosome mRNA tRNA
What represents Chargaff's discovery about the amounts of the nitrogenous bases A, G, C, and T in the DNA molecule?
amount of A = amount of T; amount of G = amount of C
In adult humans that can digest milk, ______ is modified so that the lactase gene is able to be transcribed.
an enhancer
What describes a ribosome?
an rRNA-protein structure that is the site of translation
Select all of the following organisms that have introns in their primary mRNA transcripts.
animals eukaryotes archaea
Select all of the following that are ways to control gene expression after translation.
blocking addition of a necessary sugar to a newly synthesized protein preventing the protein from reaching its correct destination degrading the protein
nucleotide
building block of nucleic acids
What type of illness is characterized by unregulated cell division and can be caused by defective transcription factors?
cancer
In eukaryotic cells, the mRNA is altered before it leaves the nucleus. A short sequence of modified nucleotides, known as a ______ is added to the 5' end and a string of adenines called a ______ is added to the 3' end.
cap; poly-A tail
mRNA
carries the information that specifies a protein
Select all the roles that microRNAs play in regulating gene expression.
cause mRNA to be degraded bind to mRNA and prevent translation
The regulation of gene expression in eukaryotic cells allows for
cell specialization in multicellular eukaryotes.
Regulating gene expression allows cells to produce
certain proteins only when they are needed.
Epigenetics is the study of changes in gene expression due to
chemical modifications of histones or DNA bases.
Select all of the following that are mutagens.
chemicals in tobacco radioactive fallout ultraviolet radiation harmful chemicals
Select all the locations in a eukaryotic cell where DNA is found.
chloroplast mitochondrion nucleus
What is a discrete package of DNA and its associated proteins?
chromosome
In an RNA molecule, a(n) ______ is a genetic "code word" that corresponds to one amino acid.
codon
The genetic code specifies what amino acid is matched to each three-nucleotide ______ in the mRNA.
codon
Messenger RNA contains_______ , which are triplets of bases that act as "code-words" corresponding to the _________ acid monomers that make up a polypeptide.
codons;amino
As RNA is synthesized in transcription, it can curl into a three-dimensional shape that is dictated by ______ within the molecule.
complementary base pairing
tRNA
connector molecule that binds to an mRNA codon and to an amino acid
tRNA
contains an anticodon on one end that determines what amino acid binds to the other end
mRNA
contains codons specifying the order of amino acids
Select all of the following that are true about RNA.
contains the bases A, U, G, and C single-stranded, but can form loops contains the sugar ribose can act as an enzyme
codon is 2 nucleotides long
could specify 16 amino acids
codon is 1 nucleotide long
could specify 4 amino acids
codon is 3 nucleotides long
could specify 64 amino acids
During the elongation phase of translation, a _______ bond is formed between the incoming _______ acid and the growing polypeptide chain, and empty tRNAs are released from the ribosome to be reused.
covalent; amino
Plant breeders can induce mutations to
create new varieties of crop species.
A mutation that causes a single codon to be removed such that a protein lacks one amino acid is a ______ mutation.
deletion
Within the DNA double helix, the so-called backbone is composed of ______ sugars alternating with phosphate groups.
deoxyribose
The terms 3' and 5' refer to numbered carbon atoms within the ______ of DNA, and at one end of the DNA double helix, there is a free ______ on one backbone and a free ______ on the other backbone.
deoxyribose sugar; 3' carbon; 5' carbon
In humans, the production of the protein keratin in hair follicle cells and the protein hemoglobin in red blood cells is made possible by expressing
different subsets of genes in different cells.
chromosome
discrete package of DNA coiled around proteins
Select all of the following that are true about frameshift mutations.
disrupts the codon reading frame can be caused by the deletion of two nucleotides likely to change the amino acid sequence can be caused by the addition of one nucleotide
DNA has a ______ helical structure consisting of two intertwining strands of ______.
double; nucleotides
Transcription, translation, nucleotide synthesis, and modifying mRNA are all processes that require
energy.
A eukaryotic transcription factor may bind to a promoter or to a(n) ____ , a regulatory region on the DNA that lies outside the promoter and regulates transcription.
enhancer
In eukaryotes, transcription factors can bind at near or distant regulatory DNA sequences called
enhancers.
Modifications to DNA, such as methylation, that do not change the nucleotide sequence but do affect gene expression are called ______ modifications.
epigenetic
What are coding regions of eukaryotic mRNA that are translated?
exons
Select all of the following that are true about the genetic material of eukaryotes.
exons alternate with introns in DNA and immature mRNA transcripts mature mRNA molecules can contain 70 or more exons removing introns and splicing exons plays a role in gene regulation
In a(n) _____ repeat mutation, the number of copies of a three- or four-nucleotide sequence increases over several generations.
expanding
An underlying cause of Huntington Disease is a(n) ______ mutation, in which the copies of GTC increase over several generations and cause extra glutamines in the protein product of the gene.
expanding repeat
Whereas _____ wipes away most epigenetic markers on the genome, _____ does not; therefore, identical twins may accumulate epigenetic differences throughout life.
fertilization; cell division
In the Hershey and Chase experiment, radioactively-labeled sulfur was found in the ______ within one test tube, while radioactively-labeled phosphorus was found in the ______ within the other test tube, indicating that ______ was the genetic material.
fluid; bacterial cells; DNA
After translation is complete, the newly synthesized polypeptide must ______, as determined by some regions of the amino acid chain.
fold into its functional shape
Select all of the following that are examples of mutations that cause changes in chromosome structure.
fusion of chromosomes or parts of chromosomes deletion or duplication of part of a chromosome inversion of a long DNA sequence
Select all of the following that are true about the frequency of mutations that arise during DNA replication.
generally higher in bacteria averages about 1 in 100,000 bases for most genes varies among organisms and among genes
The human genome contains about 20,000-25,000 _____ scattered on its 23 pairs of _______.
genes;chromosomes
The ______ describes the correspondence of three-nucleotide codons to specific amino acids or directions for starting and stopping translation.
genetic code
Using synthetic mRNA molecules in test tubes with all the translation machinery, researchers in the 1960s deciphered the ______, which determines what amino acid is specified by each three-nucleotide ______.
genetic code; mRNA codon
A(n) _______ mutation is one that occurs in the cells that give rise to sperm or egg.
germline
Which of the following mutations can be passed from one generation to the next?
germline
A(n) _____ mutation occurs in cells that give rise to sperm and egg cells, whereas a(n) _____ mutation occurs in non-sex cells.
germline;somatic
GAG
glutamic acid
In an average mRNA molecule that has just been transcribed, the amount of genetic material devoted to introns is _____ the amount devoted to exons.
greater than
Select all of the following that are present in a bacterial operon.
group of genes promoter operator
The DNA double _____ resembles a twisted ladder, where each rail of the "ladder" (each backbone) is composed of alternating deoxyribose sugars and groups _____ joined together by _____ bonds.
helix;phosphate;covalent
Select all the functions of ribosomal RNA.
help align the ribosome with the mRNA to prepare for translation catalyze the formation of bonds between amino acids in the developing protein
Select all of the following that are functions of the 5' cap and 3' poly A tail added to mRNA after transcription in eukaryotes.
help ribosomes attach to 5' end of mRNA protect RNA from degradation
Within the DNA double helix, the nitrogenous bases in base pairs are joined by ______ bonds, which are collectively strong but can also be pulled apart if the cell needs access to the DNA.
hydrogen
DNA molecule
includes many genes
Geneticists can study development and gene function by
inducing mutations in model organisms.
A(n) ____ is a portion of RNA that averages about 1,000 nucleotides long and that is removed before translation.
intron
What process describes the removal of spacer portions of mRNA to produce mRNA consisting of regions to be translated?
intron removal and splicing together of exons
In eukaryotes, a part of an mRNA molecule that is removed before translation is called a(n)
intron.
In eukaryotic cells, the mRNA is altered before it leaves the nucleus. After transcription,______ are removed from mRNA, and _____ are spliced together to form the mature mRNA.
introns;exons
As described by Jacob and Monod, what E. coli genes and regulatory sequences are only produced when the bacteria need to break down lactose in the immediate environment?
lac operon
Transcription of the three genes in the lac operon occurs when
lactose is present in the environment and binds to the repressor.
The lac operon in E. coli bacteria includes three genes that produce
lactose-degrading proteins.
Each ribosome has one ____ subunit and one _____ subunit that join at the initiation of protein synthesis.
large; small
When Griffith mixed together live strain R bacteria and heat-killed S bacteria and injected them into mice, the mice died, and ______ bacteria were isolated from the mice, indicating that something could pass between cells and transform them.
live S strain
Select three types of RNA.
mRNA tRNA rRNA
What mechanism allows eukaryotic cells to control gene expression by preventing translation?
mRNA degradation
To determine which codons correspond to which amino acids, scientists synthesized _____ and put them in a test tube containing the ingredients for translation. They then analyzed the resulting _____.
mRNA molecules; proteins
In transcription, the genetic information in DNA is copied into a(n) ______ molecule, and in translation, the "message" in an mRNA molecule is translated into a(n) ______ sequence.
mRNA; amino acid
During the elongation stage of translation, the ribosome exposes codons on the ______ one at a time; each codon determines what ______ will bring its attached amino acid to the ribosome to be added to the polypeptide chain.
mRNA; tRNA
During production of a protein, the information encoded in a DNA base sequence is transcribed to produce a molecule of _____ , which is then processed and translated to produce the sequence of _____ acids in a protein.
mRNA;amino
The type of RNA that carries the information to specify a protein is called
messenger RNA (mRNA).
If a substitution mutation changes a codon such that it specifies a different amino acid, it is called a ______ mutation.
missense
This figure shows the genetic difference between two versions of the hemoglobin gene, one that produces normal red blood cells and one that results in sickled red blood cells. What class of mutation does the sickle cell mutation represent?
missense substitution mutation
Some eukaryotic organelles, such as _____ and____ , contain their own genomes in addition to the cell's nuclear DNA.
mitochondria;chloroplast
A transposable element is a short DNA sequence that can cause mutations because it
moves and inserts randomly within the genome.
A(n) _____ is any external agent, such as X-rays or chemicals, that induces mutations.
mutagen
A(n) ____ is a change in a cell's DNA sequence.
mutation
A change in a protein-encoding DNA sequence or a regulatory DNA sequence, such as an enhancer, is called a(n)
mutation.
Because of ______, the "language gene" (FOXP2) in humans has two unique amino acids compared to other primates.
mutations
Homeotic genes control the formation of body parts in many animals, and ______ in homeotic genes have led to limb modifications that profoundly influenced animal evolution.
mutations
Inversions, duplications, or deletions of parts of chromosomes are types of ______ that affect extensive regions of DNA.
mutations
What allows some bacteria to develop resistance to antibiotics and give rise to resistant descendants?
mutations
A substitution mutation that changes an amino acid into a "stop" codon is called a(n) ______ mutation and shortens the protein product.
nonsense
Subunits called ______ are the building blocks of nucleic acids, as determined by scientists by about 1930.
nucleotides
In the synthesis of RNA from DNA, the enzyme RNA polymerase adds ______ to the ______ end of the growing RNA molecule.
nucleotides; 3 prime
A major difference between eukaryotic and prokaryotic chromosomes is that in eukaryotes, multiple, linear chromosomes are housed within an organelle called the ______ , and each chromosome consists of DNA associated with proteins.
nucleus
In eukaryotic cells, transcription occurs in the ______, whereas translation occurs in the ______.
nucleus; cytoplasm
mRNA processing, mRNA exit from the nucleus
occurs after transcription but before translation
protein degradation
occurs after translation
transcription factors
occurs at initiation of transcription
DNA availability
occurs before transcription
Where would you find a transcriptional terminator sequence?
on a DNA sequence
What describes a substitution mutation?
one DNA base is replaced with another
In bacterial operons, if a repressor protein binds to a sequence on the DNA called a(n) ______, transcription is inhibited.
operator
The antiparallel configuration of the DNA double helix means that the two strands of nucleotides are oriented in ______ directions with respect to each other.
opposite
UUC
phenylalanine
Select all of the following that are components of nucleotides.
phosphorus-containing groups sugar nitrogen-containing base
During the Hershey-Chase experiment, radioactive ______ was used to label the DNA, and radioactive ______ was used to label the protein.
phosphorus; sulfur
What RNA modification in eukaryotes decreases the chances that the mRNA will be degraded before translation?
poly A tail
RNA ______ is the enzyme that builds the RNA chain during transcription.
polymerase
Enzymes and chaperone proteins assist in ______ that takes place after translation is complete.
polypeptide folding
Some proteins are composed of multiple ______ that join together after translation.
polypeptides
What mechanism of regulating gene expression acts after RNA processing but before translation?
preventing mRNA exit from the nucleus
Select ways that cells increase the speed of protein synthesis.
produce multiple copies of each mRNA multiple ribosomes simultaneously translate an mRNA
Splicing of different exons together from the same mRNA molecules can result in
production of different proteins.
CCA
proline
The ______ is a sequence of DNA that signals the start of a gene and is the site where RNA polymerase binds to begin transcription.
promoter
A change in the amino acid sequence of a protein can cause the protein to be nonfunctional because ______ is affected by the amino acid sequence.
protein folding
Having multiple ribosomes bound to an mRNA is one way a cell increases the rate of
protein synthesis.
Messenger RNA carries information that specifies the amino acid sequence of a
protein.
When Avery, McCarty, and MacLeod treated a solution from the S strain bacteria with a ______-destroying enzyme, it retained its ability to transform R strain bacteria into the lethal S strain. However, when they treated the same solution with a ______-destroying enzyme, it lost its ability to transform the R strain into a killer.
protein; DNA
During translation, a(n) ______ is produced from the information that is encoded in a(n) ______.
protein; RNA molecule
Ribosomes are composed of rRNA and ______.
proteins
In the "central dogma," information flows from DNA to RNA to
proteins.
Proteins combine with ______ to form a ribosome.
rRNA
In the Hershey and Chase experiment, ______ was found inside the infected bacteria, indicating that the labeled viral ______ had entered the bacterial cells to direct new virus production.
radioactive phosphorus; DNA
Bacterial cells and skin cells are more likely to accumulate mutations than other types of cells because they
replicate their DNA and divide frequently.
A protein that binds to the operator sequence in bacterial DNA and prevents transcription of genes is called the
repressor.
Select all of the following that are true of a nonsense mutation.
results in a shortened protein product could be caused by a codon change from UGG to UGA polypeptide synthesis terminates prematurely
The sugar in RNA nucleotides is called ______, whereas the sugar in DNA nucleotides is called ______.
ribose; deoxyribose
RNA differs from DNA chemically because RNA nucleotides contain the sugar ______, and in RNA, the nitrogenous base ______ is substituted for thymine.
ribose; uracil
A complex of rRNA and proteins called a(n) ____ is the physical location of protein synthesis.
ribosome
What structures are the sites of protein synthesis and are found free in the cytosol of the cell or attached to the rough endoplasmic reticulum?
ribosomes
What role does DNA play in the cell?
store genetic information
A(n) ______ mutation is caused by the replacement of one nucleotide with another.
substitution
In the DNA double helix, the two backbones are composed of alternating
sugar and phosphate groups.
During translation elongation, what molecule brings amino acids to the ribosome, as dictated by the sequence of codons on the mRNA?
tRNA
______ is a type of RNA that serves as a "connector" between the mRNA codon and a particular amino acid.
tRNA
An anticodon is a sequence found on a(n) ______ molecule, whereas a codon is a sequence found on a(n) ______ molecule.
tRNA; mRNA
The DNA strand that is "read" during transcription is called the ______ strand.
template
The promoter is a sequence on the ______ that signals the start of a gene.
template strand of DNA
A specific sequence on the DNA called a(n) ______ sequence signals the end of a gene during transcription.
terminator
Which of the following best describes translation?
the "reading" of an mRNA to produce a protein
At the beginning of transcription, RNA polymerase binds to
the promoter.
Wilkins and Franklin performed X-ray diffraction that revealed details about
the three-dimensional shape of the DNA molecule.
Complementary base pairing within a single RNA molecule determines
the three-dimensional shape.
A C-G base pair in a DNA double helix is joined by ______ between the bases.
three hydrogen bonds
In a frameshift mutation, nucleotides are added or deleted in any number other than a multiple of
three.
DNA contains the nitrogenous base ______, whereas RNA does not contain this base but instead uses uracil.
thymine
In the 1950s, the biochemist Erwin Chargaff found that in DNA, the amount of the nucleotide base adenine always equals the amount of the nucleotide base _______ , and the amount of the nucleotide base cytosine always equals the amount of the nucleotide base ________ .
thymine;guanine
Select all of the reasons why eukaryotic cells regulate gene expression.
to coordinate early development to activate different genes at different times in the life of an organism to express different subsets of genes in different types of cells
Select all the reasons a cell regulates gene expression.
to have a specialized function to respond to changing conditions
In the central dogma, DNA is ______ into RNA, which is ______ into a sequence of amino acids.
transcribed; translated
In eukaryotic cells, proteins called ______ factors bind at specific DNA sequences, which allows RNA polymerase to initiate transcription.
transcription
In what process does the cell make a complementary RNA molecule from a DNA sequence?
transcription
A signal molecule binding to a target cell can turn on eukaryotic gene transcription by activating a
transcription factor.
In eukaryotes, what regulatory proteins are required for RNA polymerase to bind to the promoter and initiate transcription?
transcription factors
The image is showing what process in eukaryotes?
transcription initiation
Transcription factors are eukaryotic proteins that are required for RNA polymerase to bind to a promoter and initiate
transcription of genes.
Eukaryotic cells can compact their DNA or add methyl groups to make their DNA unavailable for
transcription.
In ______, a cell copies a gene's DNA sequence to a complementary RNA molecule. Then, in _____, the information in RNA is used to manufacture a protein by joining a specific sequence of amino acids into a polypeptide chain.
transcription;translation
In the "central dogma" describing the flow of genetic information from DNA to protein, DNA is copied to RNA in a process called ____ , and the information in RNA is used to direct the synthesis of a protein in a process called ______.
transcription;translation
What type of RNA binds to an mRNA codon at one end and a specific amino acid at the other end?
transfer RNA (tRNA)
In what process does the cell use the information in an RNA molecule to assemble a protein?
translation
What is a DNA sequence that can cause mutation by randomly inserting into a gene and disrupting its function?
transposon
Select all of the following that are actions of the enzyme RNA polymerase.
unzip the DNA to expose the template strand build an mRNA chain attach to the promoter on DNA
Which of the following best describes transcription?
using a DNA template to synthesize RNA
Mutations can be harmful, but they also provide the ______ that makes evolution possible.
variation
In the Hershey-Chase experiment in 1950, ______ were labeled with two types of radioactive markers, one that marked protein and one that marked ______, and then allowed to infect E. coli bacteria.
viruses; DNA
Select all the ways that cells can make DNA less available for transcription.
wind DNA more tightly tag DNA with methyl groups
