Chapter 6 Flashcards
_____ is a molecule that contains instructions for the functions of every cell and carries a record of evolutionary history.
a. DNA
b. ATP
c. Phosphate
d. Protein
e. Sugar
DNA
When regulatory proteins bind to an operator to block RNA polymerase, that is called ______. When regulatory proteins bind to an enhancer, that is called _____.
a. operator control; enhancer control
b. negative control; positive control
c. silencing; transcription
d. post-transcription regulation; pre-transcription regulation
e. epigenetics; methylation
negative control; positive control
What is the difference between a point mutation and a chromosomal aberration?
a. Point mutations occur at a specific point due to sunlight, whereas chromosomal aberrations can occur anywhere due to any type of DNA damage.
b. A chromosomal aberration is an all-inclusive term for any DNA mutation, and a point mutation is a type of aberration.
c. A chromosomal aberration is caused by DNA damage, while a point mutation is a mutation of a single base.
d. Both are mutation types, but in a point mutation, one base pair is changed, and in a chromosomal aberration, an entire section of the chromosome is altered.
e. Both are mutation types, but in a point mutation, the mutation occurs at a specific point anywhere on the chromosome. In a chromosomal aberration, the mutation is all throughout the chromosome.
Both are mutation types, but in a point mutation, one base pair is changed, and in a chromosomal aberration, an entire section of the chromosome is altered.
In DNA, which nitrogenous base pairs with adenine?
a. adenine
b. deoxyribose
c. guanine
d. cytosine
e. thymine
thymine
DNA is found in all of these organisms except _____.
a. humans
b. corn
c. apes
d. salamanders
e. DNA is found in all living organisms
DNA is found in all living organisms
RNA polymerase binds to the _______ of a gene to begin transcription.
a. intron
b. termination site
c. promoter site
d. operator
e. “stop” codon
promoter site
Most heritable human diseases are the result of mutations in _____ proteins, resulting in a toxic build-up of molecules.
a. enzymatic
b. regulatory
c. housekeeping
d. structural
e. operon
enzymatic
How is DNA organized in a human cell?
a. There are many strands, each consisting of 1 gene.
b. There are several strands, which are called genomes.
c. There is one circular loop of DNA.
d. There is one long strand of DNA.
e. There are 46 strands, called chromosomes.
There are 46 strands, called chromosomes.
The first step of transcription is:
a. DNA polymerase uses the information in DNA to create an mRNA transcript.
b. A transcript’s start sequence is recognized, and ribosomal subunits assemble.
c. RNA polymerase recognizes and binds to the gene’s promoter site.
d. RNA polymerase recognizes a promoter site and detaches from the DNA molecule.
e. A cap and tail are added to the transcript
RNA polymerase recognizes and binds to the gene’s promoter site.
Which statement is true concerning mutations and evolution?
a. Genes do not play a role in evolution.
b. Mutations increase fitness by producing effects that make individuals more likely to reproduce.
c. Mutations always result in the ability to outcompete competitors.
d. Mutations always cause disease and, therefore, thin out populations.
e. Mutations are a source of genetic variation.
Mutations are a source of genetic variation.
Most genes come in alternative forms called:
a. heterozygotes.
b. gametes.
c. homozygotes.
d. chromosomes.
e. alleles.
alleles.
- How many RNAs can be transcribed from a single DNA template?
a. Two RNAs per DNA template can be transcribed, because DNA is double-stranded.
b. Four RNAs, two per DNA strand, can be transcribed.
c. Only one RNA per DNA template can be transcribed.
d. It depends on the length of the DNA template strand.
e. Hundreds of RNAs can be transcribed from a single DNA template
Hundreds of RNAs can be transcribed from a single DNA template
Which statement about insertion, deletion, and substitution point mutations is true?
a. Insertion and deletion point mutations never change the sequence of amino acids in the polypeptide chain.
b. Insertion and deletion point mutations always shorten proteins.
c. Insertion and deletion point mutations alter the reading frame from the point of mutation to the end of the gene.
d. Substitution mutations always result in an amino acid substitution.
e. Substitution mutations can alter the reading frame from the point of mutation to the end of the gene.
Insertion and deletion point mutations alter the reading frame from the point of mutation to the end of the gene.
In DNA, which nitrogenous base pairs with adenine?
a. guanine
b. thymine
c. adenine
d. cytosine
e. deoxyribose
thymine
Which heritable disease is due to a mutation that causes nonfunctional enzymes, leading to a toxic build-up of molecules?
a. Cystic fibrosis
b. Color blindness
c. Breast cancer
d. Sickle cell anemia
e. Tay-Sachs disease
Tay-Sachs disease
What is the difference between a point mutation and a chromosomal aberration?
a. A chromosomal aberration is caused by DNA damage, while a point mutation is a mutation of a single base.
b. Both are mutation types, but in a point mutation, one base pair is changed, and in a chromosomal aberration, an entire section of the chromosome is altered.
c. Point mutations occur at a specific point due to sunlight, whereas chromosomal aberrations can occur anywhere due to any type of DNA damage.
d. Both are mutation types, but in a point mutation, the mutation occurs at a specific point anywhere on the chromosome. In a chromosomal aberration, the mutation is all throughout the chromosome.
e. A chromosomal aberration is an all-inclusive term for any DNA mutation, and a point mutation is a type of aberration.
Both are mutation types, but in a point mutation, one base pair is changed, and in a chromosomal aberration, an entire section of the chromosome is altered.
Which example is NOT a potential mutagen?
a. X rays
b. UV rays
c. lead aprons
d. cigarette smoke
e. engine exhaust
lead aprons
Chromosomal aberrations:
a. involves gene deletions or relocations, but not duplications.
b. are changes to the overall organization of genes on a chromosome.
c. are more harmful than point mutations.
d. occur when one base pair in the DNA is substituted for another.
e. occur when a base pair is inserted or deleted.
are changes to the overall organization of genes on a chromosome.
In eukaryotes, where can one find most of an organism’s DNA?
a. gametes
b. nucleus
c. cytoplasm
d. rough ER
e. Golgi apparatus
nucleus
The production of mRNA from DNA is called:
a. replication.
b. transcription.
c. transduction.
d. translation.
e. transformation.
transcription.
A mutation that involves the addition, subtraction, or substitution of a single base is known as:
a. genetic drift.
b. a point mutation.
c. a chromosomal aberration.
d. gene flow.
e. polyploidy.
a point mutation.
The three codons that do not code for any amino acid—UAA, UAG, and UGA—are also known as:
a. nonsense codons.
b. duplicate codons.
c. “start” codons.
d. “stop” codons.
e. transfer codons
“stop” codons.
These three stop sequences—UAA, UAG, and UGA—indicate the end of translation.
“stop” codons.
In _______ disease, lipids are not broken down within the lysosomes, resulting in cell death.
Tay-Sach
All of these scientists contributed to discovering the structure of DNA, except ______________.
a. Rosalind Franklin
b. Linus Pauling
c. James Watson
d. Charles Darwin
e. Francis Crick
Charles Darwin
The enzyme _____ recognizes and binds to the DNA molecule at the promoter site and unwinds it to begin reading the gene’s information.
RNA polymerase
In_____, DNA is found in the nucleus, the control center of each eukaryotic cell.
eukaryotes
RNA polymerase catalyzes the synthesis of:
a. RNA from DNA.
b. mRNA from tRNA.
c. DNA from RNA.
d. tRNA from mRNA.
e. DNA from DNA.
RNA from DNA.
In DNA, which nitrogenous base pairs with cytosine?
a. guanine
b. thymine
c. adenine
d. cytosine
e. deoxyribose
guanine
The steps of translation occur:
a. in the smooth endoplasmic reticulum.
b. on a ribosome in the cytoplasm.
c. on the plasma membrane.
d. in the nucleus.
e. in the Golgi apparatus.
on a ribosome in the cytoplasm.
Messenger RNA (mRNA) molecules are made during transcription in the_____. They leave the nucleus and travel to a ribosome in the_____, where the steps of translation occur.
nucleus; cytoplasm
Which statement about mutations is false?
a. Mutations can be induced via ultraviolet radiation.
b. Mutations are the ultimate source of all genetic variability.
c. Mutations always decrease an organism’s fitness.
d. Somatic cell mutations do not lead to evolution.
e. Mutations occur in all species.
Mutations always decrease an organism’s fitness.
If transcription can be described as copying a recipe from a cookbook to an index card, the process of mixing ingredients and baking cookies describes _____.
a. translation
b. regulation
c. mRNA
d. the nucleus
e. RNA polymerase
translation
In_____, one nucleotide is changed, whereas in_____, entire sections of a chromosome are altered.
point mutations; chromosomal aberrations
The production of mRNA from DNA is called:
a. replication.
b. transcription.
c. transduction.
d. translation.
e. transformation.
transcription.
_____is the process by which a gene’s base sequence is copied to an mRNA transcript.
Transcription
In prokaryotes, where can one find most of an organism’s DNA?
a. gametes
b. nucleus
c. cytoplasm
d. rough ER
e. Golgi apparatus
cytoplasm
The steps of transcription occur:
a. in the smooth endoplasmic reticulum.
b. on a ribosome in the cytoplasm.
c. on the plasma membrane.
d. in the nucleus.
e. in the Golgi apparatus.
in the nucleus.
_____control lowers gene expression, whereas _____control increases gene expression.
Negative; positive
The function of DNA is:
a. storing energy.
b. storing information.
c. catalyzing chemical reactions.
d. regulating sexual development.
e. forming cell membranes.
storing information.
Mutations in ______ would have no adverse health effect on an individual; however, the mutations could be passed on to offspring.
a. somatic cells
b. stem cells
c. red blood cells
d. skin cells
e. sex cells
sex cells
Which type of molecule carries amino acids to the ribosome during protein synthesis?
a. mRNA
b. tRNA
c. short proteins
d. “start” codons
e. RNA polymerase
tRNA
_____transports specific amino acids to ribosomes, which are added to a growing polypeptide chain.
tRNA
In most eukaryotes, a large proportion of DNA does not code for proteins or RNA. By what name did some biologists refer to this noncoding DNA when it was first observed?
a. tRNA
b. mRNA
c. “stop” codons
d. junk DNA
e. alleles
junk DNA
_____are alternate forms of the same gene.
Alleles
Regulatory genes:
a. bind to DNA to start transcription.
b. signal the end of transcription.
c. code for a repressor protein that binds to an operator and blocks RNA polymerase.
d. block RNA polymerase from transcribing a gene.
e. signal the end of translation.
code for a repressor protein that binds to an operator and blocks RNA polymerase.
What is meant by the statement: “We live in the ‘Age of the Gene’”?
a. Genes have become the only way to solve any criminal cases; therefore, if there is no DNA evidence, a case cannot be proven.
b. Genetically modified organisms are being used in agriculture for the first time.
c. Increased scientific understanding and new tools of molecular biology have enabled us to explore the contribution of our genes to every aspect of life as never before in human history.
d. This generation of children are all most likely to be genetically modified.
e. Gene editing has seen widespread use as therapy for common diseases.
Increased scientific understanding and new tools of molecular biology have enabled us to explore the contribution of our genes to every aspect of life as never before in human history.
The central dogma of molecular biology states that:
a. DNA is transcribed into RNA.
b. DNA is translated into RNA, which is transcribed into protein.
c. DNA is translated into protein.
d. RNA is transcribed into polypeptides.
e. DNA is transcribed into RNA, which is translated into protein.
DNA is transcribed into RNA, which is translated into protein.
Adenine, cytosine, guanine, and thymine are the nitrogenous bases found in the DNA of which organism(s)?
a. only humans and salamanders
b. only onions
c. only humans
d. all living organisms
e. only salamanders
all living organisms
The nucleotide unit of a DNA molecule has three components: a phosphate group, a sugar, and which of the following?
a. a promoter
b. another sugar-phosphate strand
c. a carbon-containing base
d. a nitrogen-containing base
e. a nitrogen-containing acid
a nitrogen-containing base
The position of a gene on a chromosome is known as the _____.
a. locus
b. allele
c. codon
d. trait
e. genome
locus
A _____is an addition, subtraction, or change in a single base pair.
point mutation
What is the difference between a gene and an allele?
a. A gene is a sequence of bases in a DNA molecule, and an allele is an alternative version of a gene that codes for the same feature.
b. A gene is a form of a trait, and alleles make up genes.
c. A gene is a sequence of bases in a DNA molecule, and an allele is an alternative version of a gene that codes for a different, but related, feature.
d. An allele and a gene are the same thing.
e. A gene describes a chromosome, and an allele describes an exact location of a gene on a chromosome.
A gene is a sequence of bases in a DNA molecule, and an allele is an alternative version of a gene that codes for the same feature.
The process by which information in a gene’s sequence is used to synthesize a gene product (commonly a protein, but also RNA).
gene expression
The processes by which cells “turn on” or “turn off ” genes, influencing the amount of gene products formed.
gene regulation
A group of several genes, along with the elements that control their expression as a unit, all within one section of DNA.
operon
The first regulatory site of the operon
the promoter
The specific nucleotide sequence that signals the beginning of the gene
promoter region
The second regulatory site of the operon
operator
The region of DNA to which a repressor protein can bind and, by doing so, block RNA polymerase from transcribing genes.
the operator
A molecule that can bind to the operator site and block RNA polymerase from transcribing genes
repressor protein
The third regulatory element of the operon
regulatory gene
A gene that codes for a product—such as a repressor protein or activator protein—that influences the expression of one or more other genes.
regulatory gene
When a regulatory protein binds to an ____, the transcription rate for the associated gene is increased.
enhancer sequence
Alterations to chromosomes that do not change the DNA sequence but may influence the long-term activity of some genes and may be passed on to an organism’s offspring.
epigenetic changes
An alteration in the base-pair sequence of an individual’s DNA; may arise spontaneously or following exposure to a mutagen.
mutation
Which statement is true about human DNA?
a. Human genes do not have noncoding regions of DNA within them.
b. A newt, an onion, and an amoeba all have smaller genomes compared to humans.
c. Bacteria have far more noncoding regions in their DNA than humans.
d. The genome size of an organism is a good measure of the complexity of that organism.
e. Fruit flies contain a greater percentage of coding DNA than do humans.
Fruit flies contain a greater percentage of coding DNA than do humans.
Which scientist is incorrectly matched to his/her role in the discovery of DNA?
a. Linus Pauling: investigated the structure of DNA.
b. Rosalind Franklin: produced X-ray pictures of DNA critical to decoding its shape.
c. James Watson: contributed to the deduction of the exact structure of DNA.
d. Francis Crick: contributed to the deduction of the exact structure of DNA.
e. Maurice Wilkins: responsible for decoding the individual base pairs of DNA.
Maurice Wilkins: responsible for decoding the individual base pairs of DNA.
Mutations in ______ would have no adverse health effect on an individual; however, the mutations could be passed on to offspring.
a. skin cells
b. red blood cells
c. somatic cells
d. sex cells
e. stem cells
sex cells
The same gene found in a species of salamander can code for orange spots, yellow spots, or blue spots. These alternate versions of a gene are known as:
a. bases.
b. ribosomes.
c. chromosomes.
d. genomes.
e. alleles.
alleles.
The third step of transcription is:
a. A cap and tail are added to the transcript.
b. A transcript’s termination sequence is recognized, stopping the transcription, and the mRNA molecule is released as a free-floating, single strand copy of the gene.
c. The DNA strand is processed through the RNA polymerase and a copy is built.
d. DNA polymerase uses the information in DNA to create an mRNA transcript.
e. RNA polymerase recognizes and binds to the gene’s promoter site.
A transcript’s termination sequence is recognized, stopping the transcription, and the mRNA molecule is released as a free-floating, single strand copy of the gene.
What is the primary product of the transcription of eukaryotic genes?
a. mRNA
b. DNA
c. rRNA
d. tRNA
e. RNA
mRNA
Mutations that lead to genetic disease commonly cause human illness because:
a. the overproduction of enzymes makes you sick.
b. a molecule normally metabolized by an enzyme accumulates to toxic levels.
c. mutations in DNA cause body cells to self-destruct.
d. most genetic diseases make people more likely to become sunburned.
e. mutations cause extra DNA to be made, which gets into your blood, causing illness.
a molecule normally metabolized by an enzyme accumulates to toxic levels
If 32% of the bases in a DNA molecule are adenine, which of the following describes the abundances of the other bases?
a. 32% cytosine, 18% thymine, 18% guanine
b. 32% thymine, 18% cytosine, 18% guanine
c. 16% thymine, 16% guanine, 16% cytosine
d. 18% cytosine, 32% guanine, 18% thymine
e. 32% thymine, 32% guanine, 4% cytosine
32% thymine, 18% cytosine, 18% guanine
If a tRNA’s attachment site has the sequence GAU, it will match with which corresponding codon?
a. CTA
b. GAU
c. GUT
d. CUA
e. CUT
CUA
Acute myelogenous leukemia is a rare bone marrow cancer caused by a gene breaking off from one chromosome and becoming attached to a different chromosome. What type of mutation does this describe?
a. nucleotide deletion
b. gene duplication
c. gene deletion
d. gene relocation
e. nucleotide insertion
gene relocation
Which statement about the discovery of DNA structure by Watson and Crick is false?
a. From the structure of DNA, it was clear how genes encoded information for proteins.
b. Hydrogen bonds were shown to hold the two strands of DNA together.
c. Determining the structure of DNA almost immediately revealed how chromosomes duplicate.
d. X-ray pictures of DNA were helpful in deducing its structure.
e. Because of base pairing, there always is an equal number of G and C, and A and T.
From the structure of DNA, it was clear how genes encoded information for proteins.
Which statement about DNA is false?
a. Cells in specialized tissue contain only the genes necessary for the function of those tissues.
b. Cells in specialized tissue contain only the genes necessary for the function of those tissues.
c. In eukaryotes, translation of mRNA into protein occurs outside of the nucleus.
d. Prokaryotes have a circular genome, located in the cytoplasm.
e. The genes carried within an organism’s DNA are known as its genotype.
f. RNA polymerase is the machinery responsible for transcription.
Cells in specialized tissue contain only the genes necessary for the function of those tissues.
