Transcript
Biology: Concepts and Connections, 6e (Campbell)
Chapter 11
How Genes Are Controlled
Multiple-Choice Questions
1) Which of the following statements about the problems created by cloning is false?
A) Cloned animals are less healthy than animals created by natural methods.
B) Cloning does not increase genetic diversity in the cloned species.
C) Cloning endangered species may de-emphasize the need to preserve critical natural habitats.
D) Cloned animals live longer compared to naturally bred animals.
E) Cloning leads to malfunctions in gene regulation.
Answer: D
Topic: Opening Essay
Skill: Factual Recall
2) The fact that the nucleus from an adult somatic cell can be used to create all of the cell types in a new organism demonstrates that development depends upon
A) the control of gene expression.
B) the timing of mitosis and meiosis.
C) the timing of meiosis and cell migrations.
D) the deposition of materials in the extracellular matrix.
E) the position of cells within an embryo.
Answer: A
Topic: Opening Essay
Skill: Conceptual Understanding
3) The term "gene expression" refers to the
A) fact that each individual of a species has a unique set of genes.
B) fact that individuals of the same species have different phenotypes.
C) process by which genetic information flows from genes to proteins.
D) fact that certain genes are visible as dark stripes on a chromosome.
E) flow of information from parent to offspring.
Answer: C
Topic: 11.1
Skill: Conceptual Understanding
4) A gene operon consists of
A) a transcribed gene only.
B) a promoter only.
C) a regulatory gene only.
D) transcribed genes, an operator, and a promoter.
E) transcribed genes, a promoter, and a regulatory gene.
Answer: D
Topic: 11.1
Skill: Factual Recall
5) In a prokaryote, a group of genes with related functions, along with their associated control sequences, defines
A) an allele.
B) an operon.
C) a locus.
D) a transposon.
E) a chromosome.
Answer: B
Topic: 11.1
Skill: Factual Recall
6) The lac operon in E. coli
A) prevents lactose-utilizing enzymes from being expressed when lactose is absent from the environment.
B) coordinates the production of tryptophan-utilizing enzymes when it is present.
C) allows the bacterium to resist antibiotics in the penicillin family.
D) regulates the rate of binary fission.
E) uses activators to initiate the production of enzymes that break down lactose.
Answer: A
Topic: 11.1
Skill: Conceptual Understanding
7) Proteins that bind to DNA and turn on operons by making it easier for RNA polymerase to bind to a promoter are called
A) regulators.
B) inhibitors.
C) operators.
D) activators.
E) repressors.
Answer: D
Topic: 11.1
Skill: Factual Recall
8) The lac operon of E. coli is ________ when the repressor is bound to lactose.
A) active
B) inactive
C) elongated
D) cloned
E) unregulated
Answer: A
Topic: 11.1
Skill: Factual Recall
9) The expression of the tryptophan operon is controlled by
A) a repressor that is active when it is alone.
B) a repressor that is inactive when it binds to lactose.
C) a repressor that is active when it binds to tryptophan.
D) an activator that turns the operon on by binding to DNA.
E) an activator that permanently deletes genes in the tryptophan operon.
Answer: C
Topic: 11.1
Skill: Conceptual Understanding
10) Which of the following is likely to occur in E. coli cells that are grown in skim milk?
A) The lac operon is shut off and the cells will not produce lactose-utilizing enzymes.
B) The trp repressor is activated and the cells will produce lactose-utilizing enzymes.
C) The trp operon is turned on but the bacteria will not produce lactose-utilizing enzymes.
D) The trp operon and the lac operon are both switched off.
E) The trp operon and the lac operon are both switched on.
Answer: B
Topic: 11.1
Skill: Conceptual Understanding
11) A single cell, the zygote, can develop into an entirely new organism with many different specialized cells. Which of the following statements about this process is false?
A) Additional genetic information for the formation of specialized cells is passed on to the developing embryo via the
placenta.
B) The descendant cells specialize by a process known as cellular differentiation.
C) The zygote contains all of the genetic information required for the development of many different cell types.
D) Only some of the genes in the zygote are expressed in all of its descendant cells.
E) Differentiation of the zygote into a multicellular organism results from selective gene expression.
Answer: A
Topic: 11.2
Skill: Conceptual Understanding
12) The genes for the enzymes of glycolysis
A) are active in all metabolizing cells, but the genes for specialized proteins are expressed only in particular cell types.
B) are inactive in all metabolizing cells, but the genes for specialized proteins are expressed in all cell types.
C) and the genes for all specialized proteins are expressed in all metabolizing cells.
D) and the genes for specialized proteins are expressed in all nonembryonic cell types.
E) and the genes for all specialized proteins are expressed in all embryonic cells.
Answer: A
Topic: 11.2
Skill: Conceptual Understanding
13) Which of the following statements regarding DNA packing is false?
A) A nucleosome consists of DNA wound around a protein core of eight histone molecules.
B) DNA packing tends to promote gene expression.
C) Histones account for about half the mass of eukaryotic chromosomes.
D) Highly compacted chromatin is generally not expressed at all.
E) Prokaryotes have proteins analogous to histones.
Answer: B
Topic: 11.3
Skill: Factual Recall
14) The relationship between DNA and chromosomes is most like
A) an egg yolk inside of an egg.
B) a dozen eggs packaged within an egg carton.
C) a spoon cradling some peas.
D) thread wrapped around a spool.
E) the candy shell surrounding the chocolate in a piece of M & M candy.
Answer: D
Topic: 11.3
Skill: Conceptual Understanding
15) In female mammals, the inactive X chromosome in each cell
A) becomes a nucleotroph corpus.
B) can be activated if mutations occur in the active X chromosome.
C) is broken down, and its nucleotides are degraded and reused.
D) is absorbed and used in energy production.
E) becomes a Barr body.
Answer: E
Topic: 11.4
Skill: Conceptual Understanding
16) The tortoiseshell pattern on a cat
A) usually occurs in males.
B) is the result of a homozygous recessive condition.
C) results from X chromosome inactivation.
D) is a result of alleles on the Y chromosome.
E) occurs in male cats 25% of the time and in female cats 50% of the time.
Answer: C
Topic: 11.4
Skill: Conceptual Understanding
17) Both prokaryotic and eukaryotic cells use ________ to turn certain genes on or off.
A) DNA ligase
B) RNA transcriptase
C) intron segments
D) regulatory proteins
E) nucleosome packing
Answer: D
Topic: 11.5
Skill: Factual Recall
18) Enhancers are
A) adjacent to the gene that they regulate.
B) required to turn on gene expression when transcription factors are in short supply.
C) the site on DNA to which activators bind.
D) required to facilitate the binding of DNA polymerases.
E) the products of transcription factors.
Answer: C
Topic: 11.5
Skill: Factual Recall
19) Silencers are sites in DNA that
A) bind RNA promoters to promote the start of transcription.
B) bind enhancers to promote the start of transcription.
C) bind repressor proteins to inhibit the start of transcription.
D) bind activators to inhibit the start of transcription.
E) release mRNA.
Answer: C
Topic: 11.5
Skill: Factual Recall
20) RNA splicing involves the
A) addition of a nucleotide "cap" to the molecule.
B) addition of a nucleotide "tail" to the molecule.
C) removal of introns from the molecule.
D) removal of exons from the molecule.
E) addition of introns to the molecule.
Answer: C
Topic: 11.6
Skill: Factual Recall
21) The coding regions of a gene (the portions that are expressed as polypeptide sequences) are called
A) introns.
B) exons.
C) redundant coding sections.
D) proto-oncogenes.
E) nucleosomes.
Answer: B
Topic: 11.6
Skill: Factual Recall
22) Which of the following permits a single gene to code for more than one polypeptide?
A) retention of different introns in the final version of the different mRNA strands
B) alternative RNA splicing
C) protein degradation
D) genetic differentiation
E) addition of different types of caps and tails to the final version of the mRNA strands
Answer: B
Topic: 11.6
Skill: Factual Recall
23) Small pieces of RNA that can regulate mRNA transcription are called
A) microRNA.
B) minuteRNA.
C) miniRNA.
D) monoRNA.
E) minorRNA.
Answer: A
Topic: 11.7
Skill: Factual Recall
24) miRNA can be used by
A) researchers to induce the production of more mRNA.
B) researchers to stimulate the production of DNA.
C) researchers to artificially turn on gene expression.
D) viruses to stop the production of new proteins.
E) cells to prevent infections from double-stranded RNA viruses.
Answer: E
Topic: 11.7
Skill: Factual Recall
25) Which of the following statements regarding RNA and proteins is false?
A) Some genes are edited before they are translated.
B) Some polypeptides are edited to make them functional.
C) The length of time that mRNA remains functional in the cytoplasm is quite variable.
D) In eukaryotes, the lifetime of a protein is closely regulated.
E) In eukaryotes, one gene controls the production of just one functioning protein.
Answer: E
Topic: 11.6, 11.8
Skill: Factual Recall
26) All of the following mechanisms are used to regulate protein production except
A) controlling the start of polypeptide synthesis.
B) protein activation.
C) protein breakdown.
D) DNA editing.
E) the breakdown of mRNA.
Answer: D
Topic: 11.8
Skill: Factual Recall
27) The textbook authors' analogy between the regulation of gene expression and the movement of water through pipes includes all of the following except
A) the web of control that connects different genes.
B) pretranscriptional events.
C) post-transcriptional events.
D) the editing of RNA.
E) the multiple mechanisms by which gene expression is regulated.
Answer: A
Topic: 11.9
Skill: Factual Recall
28) Which of the following mechanisms of controlling gene expression occurs outside of the nucleus?
A) adding a cap and tail to RNA
B) transcription
C) DNA packing/unpacking
D) RNA splicing
E) translation
Answer: E
Topic: 11.9
Skill: Factual Recall
29) Which of the following statements about fruit fly development is false?
A) One of the earliest development events is the determination of the head and tail ends of the egg.
B) The location of the head and tail ends of the egg is primarily determined by the location of sperm entry during
fertilization.
C) Cell signaling plays an important role in the development of fruit flies.
D) Homeotic genes regulate batteries of other genes that direct the anatomical identity of body parts.
E) Cascades of gene expression routinely direct fruit fly development.
Answer: B
Topic: 11.10
Skill: Factual Recall
30) A homeotic gene
A) turns on the genes necessary for synthesis of proteins.
B) serves as a master control gene that functions during embryonic development by controlling the developmental fate of
groups of cells.
C) represses gene transcription and promotes mRNA translation.
D) produces a product that controls the transcription of other genes.
E) is found only in adult somatic cells.
Answer: B
Topic: 11.10
Skill: Conceptual Understanding
31) Which of the following statements about microarrays is false?
A) Microarrays enable scientists to determine the activity of thousands of genes at once.
B) Microarrays use tiny portions of double-stranded RNA fragments from a large number of genes.
C) Microarrays are used to determine which genes are active in different tissues or in tissues of different states of health.
D) Microarrays use fluorescently labeled cDNA molecules to identify particular genes expressed at a particular time.
E) Microarrays help scientists understand how genes interact, particularly during embryonic development.
Answer: B
Topic: 11.11
Skill: Factual Recall
32) Animal development is directed by
A) cell receptors that detect transcription factors.
B) the availability of certain "key" nutrients as cells divide.
C) signal transduction pathways.
D) cell-to-cell signaling.
E) cell-to-cell signaling and signal transduction pathways.
Answer: E
Topic: 11.10, 11.12
Skill: Factual Recall
33) To initiate a signal transduction pathway, a signal binds to a receptor protein usually located in the
A) cytosol.
B) nucleus.
C) plasma membrane.
D) ER.
E) cytoplasm.
Answer: C
Topic: 11.12
Skill: Factual Recall
34) Transcription factors attach to
A) DNA.
B) signal molecules.
C) plasma membrane receptors.
D) proteins.
E) mRNA.
Answer: A
Topic: 11.12
Skill: Factual Recall
35) A signal outside a cell triggers changes in the transcription and translation inside the cell through the process of
A) post-translational editing.
B) signal transduction pathways.
C) protein activation.
D) protein breakdown.
E) X chromosome inactivation.
Answer: B
Topic: 11.12
Skill: Conceptual Understanding
36) The basis of cellular differentiation is
A) the operon.
B) cellular specialization.
C) selective gene expression.
D) cloning.
E) mutation.
Answer: C
Topic: 11.12, 11.14
Skill: Conceptual Understanding
37) Yeast are able to communicate with each other
A) by close cell-to-cell contact.
B) with signal transduction pathways.
C) only if they can touch each other and have merged cell walls.
D) with pseudopodia.
E) only when a yeast cell has died and released its internal organelles into the external environment.
Answer: B
Topic: 11.13-Evolution Connection
Skill: Conceptual Understanding
38) Signal transduction pathways
A) are found strictly in multicellular organisms for cell-to-cell communication.
B) first appeared in animals when primates began to walk upright.
C) are limited for use in sexual identification.
D) originally evolved in vertebrates.
E) are mechanisms of communication that evolved in the ancient prokaryotes.
Answer: E
Topic: 11.13-Evolution Connection
Skill: Conceptual Understanding
39) Most differentiated cells retain
A) only a tiny fraction of their original set of genes.
B) only a tiny fraction of their original set of genes, but can regenerate lost genes as needed.
C) a complete set of their genes, but lose the ability to express most of those genes.
D) a complete set of their genes, and retain the ability to express those genes under certain circumstances.
E) the ability to dedifferentiate, but then cannot return to their original differentiated state.
Answer: D
Topic: 11.14
Skill: Conceptual Understanding
40) Why can some plants be cloned from a single cell?
A) Plant cells do not differentiate even when mature, so any cell can grow into an entire plant.
B) Plant cells can dedifferentiate and give rise to all of the specialized cells required to produce an entire plant.
C) Plant cells are able to retrieve genes lost to the environment during development.
D) Plant cells can produce genes to replace those lost during development.
E) Plant cells are capable of self-renewal by utilizing cellular components from adjacent cells .
Answer: B
Topic: 11.14
Skill: Conceptual Understanding
41) Which of the following processes occurs when a salamander regenerates a lost limb?
A) Oncogenes that cause accelerated cell division are turned on.
B) Certain cells in the limb dedifferentiate, divide, and then redifferentiate to form a new limb.
C) A new salamander develops from the lost limb.
D) The homeotic genes of the regenerating cells turn off.
E) The cell cycle is arrested and apoptosis begins.
Answer: B
Topic: 11.14
Skill: Conceptual Understanding
42) The cloning of Dolly the sheep
A) demonstrated that the nuclei from differentiated mammalian cells can retain their full genetic potential.
B) demonstrated that differentiated cells contain only a fraction of their full genetic potential.
C) demonstrated, for the first time, that eggs are haploid and body cells are diploid.
D) revealed that cloned mammals most resemble the egg donor.
E) revealed that cloned mammals most resemble the sperm donor.
Answer: A
Topic: 11.15
Skill: Factual Recall
43) Cloning to produce embryonic stem cells is called
A) regenerative cloning.
B) transplantational cloning.
C) reproductive cloning.
D) therapeutic cloning.
E) dedifferentiation.
Answer: D
Topic: 11.15
Skill: Factual Recall
44) Which of the following mammals has not yet been cloned and brought through the complete gestation cycle?
A) cow
B) human
C) pig
D) dog
E) cat
Answer: B
Topic: 11.16
Skill: Conceptual Understanding
45) Which of the following possible uses of reproductive cloning is still considered by most to be an unresolved ethical issue?
A) the production of genetically identical animals for experimentation
B) the production of potentially valuable drugs
C) the production of organs in pigs for transplant into humans
D) the improvement of the quality of farm animals
E) the production of genetically identical humans for therapeutic purposes.
Answer: E
Topic: 11.16
Skill: Conceptual Understanding
46) Which of the following statements regarding stem cells is false?
A) Embryonic stem cells can be induced to differentiate.
B) Embryonic stem cells can give rise to all the different specialized cells in the body.
C) Adult, but not embryonic, stem cells can be grown in laboratory culture.
D) Adult stem cells are present in adult tissues.
E) Adult stem cells are partway along the road to differentiation.
Answer: C
Topic: 11.17
Skill: Factual Recall
47) Adult stem cells have limited therapeutic potential
A) because they are fully differentiated.
B) because they lack a complete set of genes.
C) due to their excessive numbers in tissues.
D) because scientists have no reliable method of identification.
E) because their developmental potential is limited to certain tissues.
Answer: E
Topic: 11.17
Skill: Factual Recall
48) A gene that can cause cancer when present in a single copy in a cell is called a(n)
A) oncogene.
B) enhancer gene.
C) silencer gene.
D) carcinogen.
E) proto-oncogene.
Answer: A
Topic: 11.18
Skill: Factual Recall
49) Which of the following statements about proto-oncogenes is false?
A) Proto-oncogenes are normal genes with the potential to become oncogenes.
B) Many proto-oncogenes code for growth factors.
C) A mutation must occur in a cell's DNA for a proto-oncogene to become an oncogene.
D) A mutation in a tumor-suppressor gene can stop cell division immediately.
E) One of the earliest clues to understanding cancer was the discovery of a virus that causes cancer in chickens.
Answer: D
Topic: 11.18
Skill: Factual Recall
50) Which of the following is not a factor that contributes to normal cells becoming cancerous?
A) the conversion of a proto-oncogene to an oncogene
B) damage to a tumor-suppressor gene
C) the acquisition of an oncogene from a virus
D) one or more of the cell's genes being removed by a virus
E) excessive replication of proto-oncogenes
Answer: D
Topic: 11.18
Skill: Conceptual Understanding
51) Cancer of the colon is caused by
A) a single gene mutation.
B) several somatic cell mutations.
C) exposure of colon cells to a mutagen.
D) lack of vitamin K.
E) the proto-oncogene, lac.
Answer: B
Topic: 11.19
Skill: Factual Recall
52) The development of colon cancer occurs slowly and is more prominent in the elderly than the young. This is most likely because
A) cancer cells don't have mitochondria, so they grow slowly.
B) four or more somatic mutations must occur to give rise to the cancer, which takes time.
C) cancer cells suppress the growth of each other in a tissue.
D) cancer cells have to wait until new blood vessels grow into the area, which takes much time.
E) most cancer mutations interfere with mitosis, so cell division occurs more slowly.
Answer: B
Topic: 11.19
Skill: Conceptual Understanding
53) Mutations in the proto-oncogenes ras and p53
A) increase protein synthesis by the cell.
B) are rarely associated with cancers.
C) can improve the chance of avoiding cancer as one ages.
D) can enhance further mutations, which can develop into cancer.
E) disrupt normal regulation of the cell cycle.
Answer: E
Topic: 11.20
Skill: Factual Recall
54) Mutations in the p53 gene can lead to cancer by
A) causing the production of excessive amounts of relay proteins.
B) turning off a gene for a protein that inhibits cell division.
C) increasing the production of glycogen, which nourishes the cell cycle.
D) promoting the expression of mRNA that can interact with DNA, resulting in new mutations.
E) increasing the production of growth hormones, which trigger faster cell cycles.
Answer: B
Topic: 11.20
Skill: Conceptual Understanding
55) The carcinogen known to cause the most cases of cancer is
A) plutonium.
B) ultraviolet light.
C) alcohol.
D) salt.
E) tobacco.
Answer: E
Topic: 11.21
Skill: Factual Recall
56) Which of the following statements regarding cancer risk factors is false?
A) Factors that alter DNA and make cells cancerous are called carcinogens.
B) Mutagens are usually not carcinogens.
C) X-rays and ultraviolet radiation are two of the most potent carcinogens.
D) Eating 20-30 grams of plant fiber daily and reducing the intake of animal fat can reduce your risk of developing colon
cancer.
E) Broccoli and cauliflower are thought to be especially rich in substances that help prevent cancer.
Answer: B
Topic: 11.21
Skill: Factual Recall
Art Questions
1)
In this drawing of the lac operon, which molecule is an inactive repressor?
A) molecule A
B) molecule B
C) molecule C
D) molecule D
E) molecule E
Answer: D
Topic: 11.1
Skill: Application
2)
Which structure in this figure shows one complete nucleosome?
A) structure A
B) structure B
C) structure C
D) structure D
E) structure E
Answer: D
Topic: 11.3
Skill: Factual Recall
Scenario Questions
After reading the following paragraph, answer the question(s) below.
All apples in the United States, regardless of variety or where they're purchased, are produced by cloning. For more than 2,000 years, apple growers around the world have used a type of cloning called grafting to produce larger, better-tasting apples. Why has cloning become the primary method of apple growing? Apples grown from seeds usually don't produce apples with the same taste and appearance as that of the parent tree because there's a high degree of genetic variability among the seeds. Making identical genetic copies of the preferred fruit is the only way to get reliable apple quality.
In grafting, the shoots and branches of the desired fruit, called a scion, are attached onto the trunk and root system of a previously existing tree, called the rootstock. Both components of the graft are needed. The rootstock controls gene expression in scion, triggering production of apples that match the cloned scion.
Grafting research can be used to produce some interesting tree combinations that are beneficial for intensive agriculture. For example, if you graft the root of a small tree variety, such as the crab apple, onto the shoot from a larger apple tree, such as the Gala, you can produce Gala apples on a much smaller tree. Other scientists are trying to create disease-resistant varieties that would need less pesticides. This is beneficial for the environment and also lowers the price of apples in the grocery store.
1) Why don't the grafted hybrids produce apples with a blend of traits from the scion and the rootstock?
A) The rootstock suppresses activation of the scion genes, which alters fruit production.
B) The rootstock is unable to perform photosynthesis and so can't produce fruit.
C) Transplanted nuclei from scion cells regulate gene expression in the rootstock.
D) The rootstock regulates gene expression in the scion, but contributes no genetic information for fruit production.
E) The lac operon in the scion is the only regulator of gene expression in the hybrid.
Answer: D
Topic: 11.9, 11.14
Skill: Conceptual Understanding
2) Half the trees in an orchard were derived from rootstock "A" and half from rootstock "B," but all the trees had the same scion. If the trees grafted onto rootstock "A" were infected by a parasite that causes blossom rot, the trees grafted onto rootstock B
A) would be less likely to become infected because they're grafted onto different rootstocks.
B) would be more likely to become infected, since the pathogen would spread through the soil to the roots of other trees.
C) would be very likely to become infected, because the remaining scions are genetically identical to those that are
already infected.
D) Only half of the remaining trees are likely to become infected because they're in a different location in the orchard.
E) There's no way to determine the likelihood of infection, since genetic variability gives all the trees different
characteristics.
Answer: C
Topic: 11.9, 11.14
Skill: Conceptual Understanding
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