Chapter 11 - How Genes Control - Biol 1030
c
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.
organs
The ultimate aim of therapeutic cloning is to supply cells for the repair of damaged or diseased _________
tumor-supressor genes
This gene normally inhibits cell division or function in the repair of DNA damage, though mutations to this gene INACTIVATE it, allowing for uncontrolled division to occur
RNA interference
the use of miRNA to artificially control gene expression by injecting miRNAs (often called silencing RNAs or siRNA) into a cell to turn off a specific gene sequence
growth factor
A(n) _______ ___________ is a protein that promotes cell division. In excess, such a protein may lead to cancer.
d
Genes linked to Waardenburg syndrome in humans have also been discovered where? a. nematodes b. yeast c. plants d. jellyfish
better, therapeutic, endangered, conservation, diversity
Reproductive cloning is used to produce animals with desirable traits to: - produce _________ agricultural products - produce ____________ agents - restock populations of ___________ animals - belittle _____________ efforts - doesn't help with genetic ____________
acetylation
of DNA and histones causes nucleosomes to loosen and spread apart
oncogenes
cancer causing genes
plant cloning
a root cell can divide to form an adult plant
promoter
A specific nucleotide sequence in DNA that binds RNA polymerase and indicates where to start transcribing RNA.
methylated
genes can be passed to offspring cells; not permanent
tumor-suppressor gene
A(n) ________-__________ _______ is a gene that encodes proteins that inhibit cell division. Such proteins normally help prevent cells from becoming cancerous.
c
Adrenaline is a "fight-or-flight" hormone and is released when danger threatens or in an emergency. It binds to a protein receptor, which causes a number of reactions to occur inside the cell. Enzymes are produced that perform a number of functions, including release of sugar into the bloodstream. What function does adrenaline play in this pathway? a. receptor protein b. enzyme c. signal molecule d. relay protein
d
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 their developmental potential is limited to certain tissues.
mRNA, translation, activation, breakdown
After mRNA is fully processed and transported to the cytoplasm, gene expression can still be regulated by: - breakdown of _____ - initiation of ____________ -protein ______________ - protein _______________
c
All of the following mechanisms are used to regulate protein production except a. protein activation. b. protein breakdown. c. DNA editing. d. the breakdown of mRNA.
b
Both miRNAs and siRNAs are used in a. blocking transcription. b. blocking translation. c. enhancing transcription. d. enhancing translation.
proteins
Control of gene expression allows for cells to produce specific kinds of _______ when and where they are needed
contacting
DNA packing can PREVENT gene expression by preventing RNA polymerase and other transcription proteins from __________ the DNA
c
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. DNA sequences to which activator proteins bind. d. required to facilitate the binding of DNA polymerases.
heterochromatin
Eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed.
DNA packing
Eukaryotic chromosomes undergo multiple levels of folding and coiling, called _____ ____________
c
In multicellular eukaryotic cells, the control of gene expression is more complex because _____. a. prokaryotes are restricted to stable environments b. these cells have smaller chromosomes, so each gene must be multifunctional c. these cells are specialized for different functions d. the genes contain information for making proteins
on
Is an operon on or off when RNA polymerase is able to bind to promoter?
c
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. operators. c. activators. d. repressors.
b
RNA polyerase binds where? a. Enhancer b. Promoter c. Initiation start site d. None of the above
c
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.
a
Since the first cloned animal was produced using a fully differentiated cell, a number of observations have been made. Which of the following statements is true in regard to reproductive cloning? a. Only a small fraction of cloned embryos develop normally. b. Cloned animals are physically identical when compared to their parents. c. Cloned animals never stop growing because, similar to cancer cells, the cloned cells never stop dividing. d. Cloned animals are behaviorally identical to their parent animals.
c
The lac operon controls expression of three genes that produce lactose-digesting enzymes. What role does lactose play in regulating the lac operon? a. It is not directly involved in gene regulation in this system. b. It turns off the gene that produces the repressor protein, thereby allowing production of the three enzymes. c. It binds to and disables the repressor protein, thereby allowing production of the three enzymes. d. It binds to the promoter region of the operon, thereby allowing RNA polymerase to attach and begin transcription of the three genes.
euchromatin
The less condensed form of eukaryotic chromatin that is available for transcription.
tobacco
The only substance known to cause more cases and types of cancer than any other single agent is ___________
embryonic
_______________ stem cells are considered MORE promising than adult stem cells for medical application
LAC Operon
a gene system whose operator gene and three structural genes control lactose metabolism in E. coli
subset
a set that is part of a larger set
gene expression
overall process of information flow from genes to proteins
doesnt
Cloning ____________ increase genetic diversity
reproductive cloning
using nuclear transplantation to produce new organisms
carcinogen
A cancer-causing substance that alters DNA
mutagen
A chemical or physical agent that interacts with DNA and causes a mutation.
operon
A cluster of genes with related functions, along with the control sequences, is called an ________
barr body
A dense body formed from a deactivated X chromosome.
d
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.
oncogene
A gene that causes a cell to become cancerous is called a(n) ______________
regulatory gene
A gene that codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes.
proto-oncogene
A normal gene that, if mutated, can lead to cancer is called a(n) _______-_________
d
A proto-oncogene is a normal gene that can change into an oncogene. Oncogenes are potentially lethal genes that can cause cancer. Why do cells continue to maintain proto-oncogenes? a. Proto-oncogenes are unavoidable environmental carcinogens. b. Proto-oncogenes protect cells from infection by cancer-causing viruses. c. Proto-oncogenes are genetic junk that has not yet been eliminated by natural selection. d. Proto-oncogenes are necessary for normal control of cell division.
b
Anhydrotic dysplasia is a genetic disorder in humans that results in the absence of sweat glands in the skin. Some men have this defect all over their bodies, but in women it is usually expressed in a peculiar way. Women with this disorder typically have small patches of skin with sweat glands and other patches without sweat glands. This pattern of sweat-gland distribution can be explained by _____. a. a homeotic gene b. X chromosome inactivation c. a mutation d. alternative RNA splicing
homeotic genes
Any of the genes that control the overall body plan (anatomy) of animals by controlling the developmental fate of groups of cells.
prokaryotic
Are operons typically prokaryotic or eukaryotic?
environmental, random
Cloned animals can show differences in anatomy and behavior due to: - _______________ influences - ______________ phenomena
endangered
Cloning has been attempted to save ____________ species
nucleosomes
DNA coiled around histones
c
Dioxin is a by-product of various industrial chemical processes. It is suspected of causing cancer and birth defects in both humans and other animals. Apparently, it acts by entering cells and binding to proteins, altering the pattern of gene expression. Therefore, it is reasonable to propose that dioxin acts by mimicking _____. a. the action of DNA polymerase b. histones c. the role of transcription factors d. enhancers
x-chromosome
Either the maternal or paternal is randomly inactivated during ____-______________ inactivation
carcinogens, exercising, fiber, fat
Healthy lifestyles that reduce the risk of cancer include: 1. avoiding ____________ (ex: sun, tobacco) 2. ___________ adequately 3. high-_________, low-______ diet
linkers
Help stabilize the plasma membrane and attach cells together by joining consecutive nucleosomes
a
Hemoglobin is a molecule that is found in red blood cells. These molecules have to last for months because red blood cells have no nucleus and are unable to make more hemoglobin (they cannot transcribe from no template). However, most proteins are much shorter-lived. What is the advantage to this? a. This enables cells to maintain a precise and efficient control over their activities. b. Long-lasting proteins contribute toward tumor formation. c. Most cells have a short life span. d.Most proteins are used only once.
off
Is an operon on or off when a repressor is active?
off
Is an operon on or off when a repressor is bound to an operator?
on
Is an operon on or off when enzymes are produced?
on
Is an operon on or off when lactose is present?
subset
Most differentiated cells retain a full set of genes, even though only a ________ may be expressed
b
Mutations in the p53 gene can lead to cancer by a. causing the production of excessive amounts of relay proteins. b. causing the production of a faulty protein that is no longer able to inhibit cell division. c. promoting the expression of mRNA that can interact with DNA, resulting in new mutations. d. increasing the production of growth hormones, which trigger faster cell cycles.
division
Mutations to proto-oncogenes create cancer-causing oncogenes that stimulate cellular _________
a
Nuclear transplantation experiments provide strong evidence for which of the following? a. Differentiated vertebrate cells still maintain their full complement of DNA. b. Differentiated vertebrate cells do not maintain their full complement of DNA. c. Vertebrate cloning is not feasible. d. Cell differentiation is an irreversible process.
transcription
Once RNA polymerase attaches to the promoter once the activator proteins bind, ___________ begins
1.5%
Only about _____% of the human genome codes for proteins
c
Operons are a standard method for gene regulation in _____. a. all organisms b. eukaryotes but not prokaryotes c. prokaryotes but not eukaryotes d. E. coli, but they are rare in other organisms
c
Scientists have recently discovered a protein that seems to block HIV infection. It is called a chemokine. If expressed throughout the body, it is a possible promising treatment for HIV infection. Normal human cells contain a gene for chemokine. This single copy, however, does not get expressed enough to guard effectively against HIV infection. How could you increase the expression of the chemokine gene? a. Methylate the DNA that encodes for the chemokine gene. b. Inject a plasmid containing the chemokine gene directly into a skin cell with a needle. c. Inhibit the enzyme that removes acetyl groups from histones in the area of the DNA that encodes the chemokine gene. d. Accelerate the cell cycle in cells that contain the chemokine gene.
b
Some species of bacteria can either synthesize the amino acid glycine or absorb it from their surroundings. If glycine binds to a repressor protein, which then allows the repressor to bind to the bacterial chromosome, the operon will not be transcribed. If it is like other operons, the presence of glycine will result in the _____. a. manufacture of the repressor protein b. cessation of the synthesis of glycine c. breakdown of glycine d. inhibition of bacterial cell division
b
Spinal muscular atrophy (SMA) is caused by a mutation in the smn1 gene that is required to maintain the health of spinal motor neurons. A closely related protein, smn2, has the ability to rescue a person; however, it is often expressed in too little quantity to be beneficial. Choose the best predicted outcome if you treated an SMA patient with an miRNA complementary to the coding sequence of the smn2 gene (i.e., minus the introns). a. The miRNA would bind to the template strand of the gene and keep the DNA strand open, allowing for more copies of the gene to be made. b. The miRNA would bind to the smn2 mRNA, causing it to be broken down and fewer copies of the protein to be made. c. The miRNA would bind to the finished protein product, preventing it from doing its job and targeting it for degradation. d. The miRNA would bind to the coding strand of the smn2 gene, preventing it from being transcribed at all.
a
Stem cells could be immensely important in the treatment of which of the following conditions? a. spinal cord injuries b. lung cancer c. loss of a limb d. hardened arteries
d
Testosterone enters human cells and binds to a specific protein inside the cell. This testosterone-protein complex is then transported into the nucleus, where it binds to the cell's DNA. What is the function of the testosterone-protein complex? a. It alters the pattern of RNA splicing. b. It unwinds the DNA so that its genes can be transcribed. c. It inhibits transcription. d. It helps RNA polymerase transcribe certain genes.
genome, all
The ability to clone an animal from a single cell demonstrates that every adult body cell: 1. contains a complete __________ 2. capable of directing the production of ___ the cell types in an organism
regeneration
The ability to regrow a missing part of the body - ex: salamander
b
The basis of cellular differentiation is a. the operon. b. selective gene expression. c. cloning. d. mutation.
d
The carcinogen known to cause the most cases and types of cancer is a. plutonium. b. ultraviolet light. c. alcohol. d. tobacco.
selective
The difference between cell types are NOT due to the presence of different genes but instead due to _____________ gene expression
a
The gene for human growth factor is inserted into the E. coli lactose operon so that it replaces the structural genes with the gene for human growth factor. What substance must be added to the bacterial culture so that it produces human growth factor? a. lactose b. a repressor protein c. human growth factor d. an operator protein
c
The term "module" is often used to refer to a cluster of what? a. cells b. chromosomes c. genes d. nuclei
active, inactive, inactive, active
There are two types or repressor-controlled operons: 1. in the LAC operon, the repressor: - is ________ when alone - is __________ when bound to the lactose 2. in the TRP bacterial operon, the repressor: - is _________ when alone - is __________ when bound to the amino acid tryptophan (TRP)active,
b
To begin the process of gene transcription, RNA polymerase attaches to _____. a. the gene that will be transcribed b. the promoter associated with the target gene c. the operator associated with the target gene d. none of the above
X, UV
What are two of the most potent carcinogens? 1. _____ - rays 2. ______ radiation from sunlight
cancer
What is the second-leading cause of death in most industrialized nations?
a
Where have scientists found genes associated with breast cancer? a. nematodes b. yeast c. plants d. jellyfish
c
Which of the following is an example of homology? a. a shark tail and a whale tail b. a bird wing and a butterfly wing c. a cat forearm and a human forearm d. the body shape of a seal and the body shape of a penguin
b
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. Highly compacted chromatin is generally not expressed at all. d. Prokaryotes have proteins analogous to histones.
a
Within an operon, repressors _____. a. block gene transcription to RNA by attaching to the operator b. block gene transcription to RNA by attaching to the promoter c. block mRNA translation by attaching to the mRNA for a specific gene d. block gene transcription to RNA by attaching directly to the gene itself
b
Your body is composed of a dazzling array of different cell types. Each cell type develops its own unique properties. How does this happen? a. Each cell type is provided with its own specialized set of genes during cell division. b. All cells (with very few exceptions) contain the same set of genes, but the process of gene expression determines which genes are active in each cell. c. none of the above d. The zygote contains one of each of the different cell types. These ancestor cells then divide to produce the diversity of cell types in the adult.
p53 gene
a tumor-suppressor gene that codes for a specific transcription factor that promotes the synthesis of proteins that inhibit the cell cycle
cloning
creation of an individual by asexual reproduction
transcription factor
eukaryotic RNA polymerase requires the assistance of proteins called ___________ _______
histone
protein molecule around which DNA is tightly coiled in chromatin
repressor
protein that binds to the operator in an operon to switch off transcription (blocks RNA polymerase action)
activator proteins
proteins that bind to enhancer sequences in eukaryotes to increase transcription
activators
proteins that turn operons on by binding to DNA and stimulating gene transcription by making it easier for RNA polymerase to bind to the promoter
silencers
repressor proteins that may bind to DNA sequences and inhibit the start of transcription
microRNA
small single stranded RNA molecules that bind to mRNA and can degrade mRNA or block its translation.
adult stem cells
stem cells that are found in adults that can differentiate and form a *LIMITED* number of cells
proto-oncogenes
the corresponding normal cellular genes that are responsible for normal cell growth and division
ras proto-oncogene
the most common oncogene abnormality in tumors
nuclear transplantation
the nucleus of an egg cell or zygote is replaced with a nucleus from an adult somatic cell
cell differentiation
the process by which a cell becomes specialized for a specific structure or function
gene regulation
turning on and off of genes - deciding which ones are transcribed