Bio 003 Chapter 11

Which of the following processes occurs when a salamander regenerates a lost limb? A) Certain cells in the limb dedifferentiate, divide, and then redifferentiate to form a new limb. B) The homeotic genes of the regenerating cells turn off. C) A new salamander develops from the lost limb. D) Oncogenes that cause accelerated cell division are turned on. E) None of the choices are correct.

A) Certain cells in the limb dedifferentiate, divide, and then redifferentiate to form a new limb.

Transcription factors attach to A) DNA. B) mRNA. C) plasma membrane receptors. D) proteins. E) signal molecules.

A) DNA.

Identify a difference between embryonic and adult stem cells from the following list. A) Embryonic stem cells are undifferentiated; adult stem cells are partially differentiated. B) The use of embryonic stem cells raises fewer ethical issues than the use of adult stem cells. C) Adult stem cells are easier to grow in culture. D) It is easier to obtain embryonic stem cells. E) All of the choices are correct.

A) Embryonic stem cells are undifferentiated; adult stem cells are partially differentiated.

Why can some plants be cloned from a single cell? A) Plant cells can dedifferentiate and give rise to all of the specialized cells required to produce an entire plant. B) Plant cells do not differentiate even when mature, so any cell can grow into an entire plant. C) Plant cells can produce genes to replace those lost during development. D) Plant cells are able to retrieve genes lost to the environment during development. E) None of the choices are correct.

A) Plant cells can dedifferentiate and give rise to all of the specialized cells required to produce an entire plant.

The lac operon of E. coli is __________ when the repressor is bound to lactose. A) active B) inactive C) elongated D) unregulated E) cloned

A) active

Which is most likely to cause the development of a six-legged frog? A) mutation of homeotic genes B) a mutation in DNA polymerase that affects all cells C) conversion of a proto-oncogene to an oncogene D) binding of repressors to operons E) None of the choices are correct.

A) mutation of homeotic genes

In an operon, the ________ acts as an on/off switch. A) operator B) repressor C) promoter D) activator E) supressor

A) operator

Both prokaryotic and eukaryotic cells use which of the following to turn certain genes on or off? A) regulatory proteins B) DNA ligase C) nucleosome packing D) RNA transcriptase E) intron segments

A) regulatory proteins

The way that a signal outside a cell triggers changes in the transcription and translation inside the cell is by the process of A) signal-transduction pathways. B) protein breakdown. C) protein activation. D) X chromosome inactivation. E) post-translational editing.

A) signal-transduction pathways.

Use the accompanying figure to answer this question. The initiation of transcription requires that enhancers bind to ________. A) transcription factors B) RNA polymerase C) the promoter D) DNA E) All of the choices are correct

A) transcription factors

What can you conclude from this figure? A) The mRNA with exon 3 is longer than the mRNA with exon 4. B) Exon 3 and exon 4 are being alternatively spliced. C) This process is occurring in the cytoplasm of a eukaryotic cell. D) Exon 1 contains the stop codon for the production of a protein. E) All of the choices are correct.

B) Exon 3 and exon 4 are being alternatively spliced.

Repressors act by blocking the binding of ________ to the operator. A) the operon B) RNA polymerase C) DNA polymerase D) promoters E) activators

B) RNA polymerase

Homeotic genes ________. A) have very different sequences in plant cells as compared to animal cells B) are evidence of the common ancestry of eukaryotic organisms C) are an example of convergent evolution D) regulate gene expression in both prokaryotic and eukaryotic cells E) All of the choices are correct.

B) are evidence of the common ancestry of eukaryotic organisms

In bacteria, what name is given to a cluster of genes with related functions, along with their DNA control sequences? A) operator B) operon C) repressor D) promoter E) supressor

B) operon

To initiate a signal-transduction pathway, a signal binds to a receptor protein usually located in the A) nucleus. B) plasma membrane. C) cytoplasm. D) ER. E) cytosol.

B) plasma membrane.

The lac operon in E. coli A) uses activators to initiate the production of enzymes that break down lactose. B) prevents lactose-utilizing enzymes from being expressed when lactose is absent from the environment. C) allows the bacterium to resist antibiotics in the penicillin family. D) regulates the rate of binary fission. E) coordinates the production of tryptophan-utilizing enzymes when it is present.

B) prevents lactose-utilizing enzymes from being expressed when lactose is absent from the environment.

The tortoiseshell pattern on a cat A) is the result of a homozygous recessive condition. B) results from X chromosome inactivation. C) usually occurs in males. D) is a result of alleles on the Y chromosome. E) None of the choices are correct.

B) results from X chromosome inactivation.

Homeotic genes are important for ________. A) signal transduction pathways B) the development of an organism's body plan C) gene expression in prokaryotes D) gene regulation in eukaryotic cells E) All of the choices are correct.

B) the development of an organism's body plan

Enhancers are A) required to turn on gene expression when transcription factors are in short supply. B) the site on DNA to which activators bind. C) adjacent to the gene that they regulate. D) required to facilitate the binding of DNA polymerases. E) the products of transcription factors.

B) the site on DNA to which activators bind.

What can scientists achieve by injecting siRNAs into a cell via the process of RNA interference? A) Scientists can increase the rate of translation. B) Scientists can turn genes on. C) Scientists can prevent genes from being expressed. D) protection of the mRNA E) All of the choices are correct.

C) Scientists can prevent genes from being expressed.

Proteins that bind to DNA and turn on operons by making it easier for RNA polymerase to bind to a promoter are called A) inhibitors. B) operators. C) activators. D) repressors. E) regulators.

C) activators.

The process by which genotype becomes expressed as phenotype is ________. A) transcription B) gene regulation C) gene expression D) translation E) flow of information from parent to offspring.

C) gene expression

A gene that can cause cancer when present in a single copy in a cell is called a(n) A) carcinogen. B) enhancer gene. C) oncogene. D) silencer gene. E) proto-oncogene.

C) oncogene.

Which of the following are problems created by cloning? A) Cloned animals are less healthy than animals created by natural methods. B) Cloning endangered species may de-emphasize the need to preserve critical natural habitats. C) Cloning does not increase genetic diversity in the cloned species. D) All of the choices are problems created by cloning. E) None of the choices are problems created by cloning.

D) All of the choices are problems created by cloning.

What is the benefit of using avatars in cancer treatments? A) Avatars result in the cure for cancer. B) Avatars are used to develop new drugs to treat cancer. C) Avatars can be used to prevent the onset of cancer in young people. D) Avatars allow clinicians to identify more effective drugs to use. E) All of the choices are correct.

D) Avatars allow clinicians to identify more effective drugs to use.

Consider the accompanying figure, which outlines cloning by nuclear transplantation. Why does the clone NOT resemble the surrogate mother? A) The embryonic cells are adversely influenced by the surrogate. B) The nuclear material from the egg would influence the appearance of the clone. C) The sperm came from a male donor, who would also pass some of his traits to the clone. D) The DNA for the clone comes from the genetic donor, not the surrogate. E) None of the choices are correct.

D) The DNA for the clone comes from the genetic donor, not the surrogate.

Which is a possible result of a miRNA molecule binding to an mRNA molecule? A) addition of a cap and tail to the mRNA B) transcription of the mRNA C) protection of the mRNA D) degradation of the mRNA E) All of the choices are correct.

D) degradation of the mRNA

The lac operon is shown in the accompanying figure. The lac operon is usually in the ________ position and is activated by ________. A) off; the repressor B) on; the promoter C) on; the repressor D) off; lactose E) None of the choices are correct.

D) off; lactose

The ability to use the nucleus from an adult somatic cell to create all of the cell types in a new organism demonstrates that development depends upon A) the timing of meiosis and cell migrations. B) the position of cells within an embryo. C) the timing of mitosis and meiosis. D) the control of gene expression. E) the deposition of materials in the extracellular matrix

D) the control of gene expression.

The carcinogen known to cause the most cases of cancer is A) salt. B) ultraviolet light. C) plutonium. D) tobacco. E) alcohol.

D) tobacco.

A gene operon consists of A) a promoter only. B) transcribed genes, a promoter, and a regulatory gene. C) a transcribed gene only. D) transcribed genes and a promoter only. E) a regulatory gene only.

D) transcribed genes and a promoter only.

A gene operon consists of A) a regulatory gene only. B) a transcribed gene only. C) transcribed genes, a promoter, and a regulatory gene. D) transcribed genes and a promoter only. E) a promoter only.

D) transcribed genes and a promoter only.

Which of these is not a carcinogen? A) cigarette smoke B) testosterone C) UV light D) fat E) All of the above are carcinogens.

E) All of the above are carcinogens.

Which of the following are possible uses of reproductive cloning? A) the improvement of the quality of farm animals B) the production of genetically identical animals for experimentation C) the production of organs in pigs for transplant into humans D) the production of potentially valuable drugs E) All of the choices are correct.

E) All of the choices are correct.

Which of the following statements about breast cancer is false? A) The protein encoded by BRCA1 acts as a tumor suppressor. B) Mutations in BRCA1 and BRCA2 appear to be inherited. C) Mutations in BRCA1 put a woman at higher risk of developing breast cancer. D) Mutations in BRCA2 put a woman at higher risk of developing breast cancer. E) Most breast cancers are caused by mutations in BRCA1 or BRCA2.

E) Most breast cancers are caused by mutations in BRCA1 or BRCA2.

The genes for the enzymes of glycolysis A) and the genes for specialized proteins are expressed in all nonembryonic cell types. B) and the genes for all specialized proteins are expressed in all embryonic cells. C) are inactive in all metabolizing cells but the genes for specialized proteins are expressed in all cell types. D) and the genes for all specialized proteins are expressed in all metabolizing cells. E) are active in all metabolizing cells but the genes for specialized proteins are expressed only in particular cell types.

E) are active in all metabolizing cells but the genes for specialized proteins are expressed only in particular cell types.

Silencers are sites in DNA that A) release mRNA. B) bind enhancers to promote the start of transcription. C) bind RNA promoters to promote the start of transcription. D) bind activators to inhibit the start of transcription. E) bind repressor proteins to inhibit the start of transcription.

E) bind repressor proteins to inhibit the start of transcription.

Cloning to produce embryonic stem cells is called A) reproductive cloning. B) transplantational cloning. C) dedifferentiation. D) regenerative cloning. E) therapeutic cloning.

E) therapeutic cloning.

Which of these mechanisms of controlling gene expression occurs outside of the nucleus? A) adding a cap and tail to RNA B) DNA packing/unpacking C) RNA splicing D) transcription E) translation

E) translation

Evidence suggests that the normal version of the BRCA1 gene is as a(n) __________ gene. A) enhancer B) proto-oncogene C) homeotic D) silencer E) tumor suppressor

E) tumor suppressor