Chapter 7
Enzymes and chaperone proteins assist in ______ that takes place after translation is complete.
protein folding
How does a fever help fight a viral infection?
speeds immune responses
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.
What role does DNA play in the cell?
store instructions for making proteins
The replacement of one DNA base with another is called a(n)
substitution mutation
Only producing proteins that are needed allows a cell to
to save energy
first virus ever discovered was _______, a virus that infects over 120 plant species
tobacco mosaic virus
Eukaryotic cells can compact their DNA or add methyl groups to make their DNA unavailable for
transcription
Select all the ways that cells can make DNA less available for transcription.
tag DNA with methyl groups and wind or fold DNA in a way that makes it unavailable.
A specific sequence on the DNA called a(n) _____ sequence signals the end of a gene during transcription
terminator
latent viral infection is one in which
the viral genetic information remains inside the cell but does not cause disease symptoms.
I'm bacteria, a(n) _______ is a group of genes under control of a single promoter.
Operon
The ____ is a sequences of a DNA that signals the start of a gene and also which of the two strands of DNA is the template for transcription.
Promoter
Select all of the following that are present in a bacterial operon.
Promoter, group of genes, and operator
In the "central dogma," information flows from DNA to RNA to ______.
Proteins
Genome
all of the genetic material in a cell
A variant of a gene is referred to as a(n)
allele
On tRNA molecule, the ______ is a three-base sequence that is complementary to and binds to an mRNA codon during translation.
anticodon
What three-base site of a tRNA molecule is complementary to an mRNA codon?
anticodon
During the elongation stage of translation, a _______ bond is formed between the incoming ______ acid and the growing polypeptide chain and empty tRNAs are released from the ribosome.
covalent; amino
UV rays, X-rays, some chemicals found in tobacco, and radioactive fallout are all examples of _____, agents that can damage DNA and cause mutations.
mutagens
A change in a gene sequence or a regulatory DNA sequence is called a(n) ______.
mutation
____ provides the raw material for evolution because it can create new alleles, which are alternative forms of the same _____.
mutation; gene
The DNA double helix is made up of two strands of ___ monomers oriented in opposite directions
nucleotide
Subunits called ______ are the building blocks of DNA.
nucleotides
Messenger RNA carries information that specifies the amino acid sequence of a
protein
What is produced during translation?
protein
In eukaryotic cells, proteins called ______ factors bind at specific DNA sequences and form a pocket that allows RNA polymerase to initiate transcription.
transcription
During _______, the information that is encoded in the DNA base sequence is copied into the complementary language of mRNA. Then, once the mRNA is produced and modified, a process called _______ uses that information to assemble a sequence of amino acids.
transcription and translation
In eukaryotes, RNA polymerase cannot bind to the promoter and initiate transcription without the presence of regulatory proteins called
transcription factors
Put the following steps in the order that they occur during transcription initiation in eukaryotes, beginning with the first step at the top.
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 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.
Rank the five steps of viral replication in the order in which they occur during an infection, beginning with the first step at the top.
1. attachment to host cell 2. penetration 3. synthesis of viral components 4. assembly of new viruses 5. release of new viruses from host cell
Place in order the steps that occur in an active HIV infection cycle, beginning with the first step at the top
1.) HIV particle bonds to receptors on the host cell membrane and ans viral envelope fuses with host cell membrane. 2.) HIV contents enter the cell and reverse transcriptase transcribes the viral RNA into DNA. 3.) The DNA copy the viral genes incorporates into host DNA 4.) Viral gens are transcribed to RNA, and viral proteins are produced. 5.) Proteins coat surrounds viral RNA and viral enzymes and new HIV particles are released.
Put the following events of translational elongation(the stage in translation that occurs after initiation) in the order that they occur, beginning with the first step at the top.
1.)After the first amino acid has been brought to the ribosome, a tRNA carrying the second amino acid of a protein binds to the second codon 2.)A covalent bons forms between the first and second amino acids. 3.)The ribosomes release the first tRNA. 4.) The ribosome moves down the mRNA by one codon, and a tRNA carry the third amino acid comes into place. 5.) A covalent bons forms between the second and third amino acids 6.) the ribosome releases the second tRNA.
Gene
A sequence of nucleotides that codes for a specific protein or RNA molecule.
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 and Guanine
Select all of the bases that can be present in DNA nucleotides.
Adenine, cytosine, guanine, and thymine
Messenger RNA contains ____, which are triplets of a bases that act as "code-words" corresponding to the ____ acid monomers that make up a polypeptide.
Codons and amino
During transcription, a gene's DNA sequence is transcribed into a
Complementary RNA molecule
Select all of the following that are true about human immunodeficiency virus (HIV).
Contains the enzyme reverse transcriptase Can cause latent infections Has an RNA genome
What symptoms of influenza infection is due to dead and damaged host cells in the airway?
Cough and sore throat
During transcription, the template strand of _____ contains the nucleotides sequence that is transcribed into RNA.
DNA
The instructions in ____ encode the information that a cell needs to produce proteins, which are vital to living things.
DNA
Match each eukaryotic regulatory mechanism with where it would act within the "central dogma."
DNA availability- Occurs before transcription. 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
Epigenetics is the study of _____ that affect gene expression but do not change the DNA sequence.
DNA modifications
Where would you find a transcriptional terminator sequence?
DNA sequence
All viruses contain genetic material, which is either RNA or ____, and a(n) ____ coat that surround the genetic material.
DNA; protein
Chromosomes
Discrete package of DNA coiled around proteins
A DNA molecule consists of two intertwining strands of nucleotides that from a
Double helix
modifacations to the DNA, such as methylation, that do not change the nucleotide sequence but do affect gene expression are called _____ modifications
Epigenetic
_____ are portons of mRNA that get spliced together to form mature mRNA before translation occurs in eukaryotes.
Exons
True or False: Complementary base pairing rules state that in DNA, A pairs with G and T pairs with C.
False. A bonds with T and C bonds with G
Select the two characteristics that all viruses share.
Genetic material either RNA or DNA. A protein coat that surrounds the genetic material.
What virus is responsible for the disease AIDS?
HIV
The images shows _____, a virus that can cause latent and active infections in _______ of the immune systems
HIV; T cells
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.
A(n) ______ is a portion of mRNA that is about 1000 nucleotides long and that is removed before translation.
Intron
Select all of the reasons that gene regulation is advantageous in multicellular eukaryotic organisms.
It saves energy; not all cells need all proteins encoded in the genome.
Match each term associated with HIV infection to its correct description.
Latent HIV infection - viral genome is integrated into host genome but no new virus particles are produced Active HIV infection - viral genes are expressed, new HIV particles are produced and released Reverse transcriptase - viral enzyme that synthesizes DNA from an RNA template T cell receptor and coreceptor - interact with envelope proteins on HIV during viral attachment
In the ____ infection cycle, a bacteriophage replicates and then cause the host cell to burst, thus killing it and releasing the new viral particles.
Lytic
A(n) ______ is any external agent, such as X-rays or chemicals, that includes mutations.
Mutagen
A(n) ______ is a change in a cell's DNA sequence
Mutation or genetic mutation
During transcription, what reads the template strand within a gene and adds complementary bases?
RNA polymerase
Initiation
RNA polymerase binds to gene's promoter
Elongation
RNA polymerase moves down the template strand, adding molecules and producing a complementary RNA molecule.
Termination
RNA polymerase separates from the DNA and the newly synthesized RNA is released.
Select all of the following that can be components of RNA nucleotides
Ribose, Adenine, Guanine, and Uracil
Select all of the following that are involved in transcription initiation in eukaryotes.
TATA box; transcription factors; promoter; RNA polymerase
The DNA strand that is "read" during transcription is called the _______ strand.
Template
Select all of the following that describes RNA
The nitrogenous base uracil is used instead of thymine Can be single-stranded Nucleotides contain the sugar ribose Can catalyze chemical reactions
In a process called _____, an RNA copy of an gene sequence on the DNA molecule is made.
Transcription
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 used to direct the synthesis of a protein in a process called ____.
Transcription and Translation
True or False: Gene regulation allows cells to produce only the proteins that they need.
True
Select the true statement about viral infections of a host cell.
Viral penetration into a host cell may not cause immediate death of the host cell.
attachment, penetration, synthesis, assembly, release are the stages of
Viral replication
Bacteriophage are _____ that infect ____ cells.
Viruses: bacterial
Viruses that infect bacteria are called
bacteriophages
After a virus attaches to and penetrates a host cell, a virus can enter a phase where symptoms of the infection are delayed or it can
cause immediate cell death
Transcription, translation, nucleotide synthesis, and modification of mRNA are all processes that require
energy
What are coding regions of eukaryotic mRNA that are translated?
exons
After translation is complete, the newly synthesized protein must ______, as determined by some regions of the amino acid chain.
fold into its functional shape
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
DNA molecule
includes many genes
In archaea and eukaryotes, a part of an mRNA molecule that is removed before translation is called a(n)
intron
An animal virus can cause a(n) ______ viral infection, in which disease symptoms are not produced immediately, but the viral information remains inside the cell.
latent
In what type of bacteriophage infection does the host cell burst open, releasing the new viral particles?
lytic
What methods of gene expression regulation allows one gene to code for multiple proteins due to different combinations of exons spliced together?
mRNA processing
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
What describes a substitution mutation?
one DNA base is replaced with another
RNA _____ is the enzyme that builds the RNA chain during transcription.
polymerase
Splicing of different exons together from the same mRNA molecules can result in
production of different proteins
At the beginning of transcription, RNA polymerase binds to the _____ on the DNA.
promoter
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
In a process called _____, an RNA molecule is used to produce a protein.
translation
Preventative treatments for viruses called ____ cause the immune system to recognize molecular components of a virus without exposing the person to the disease, conferring future immunity to the target virus.
vaccines
A small, infectious agent that is composed of genetic information inside of a protein coat is called a
virus
A(n) ____ is a noncellular, small, infectious agent that is simply genetic information enclosed in a protein coat.
virus