BIOL 1030 - Chapter 11 MasteringBiology

_____ bind(s) to DNA enhancer regions. A) RNA polymerase B) Promoters C) Introns D) Activators E) Exons

D) Activators

The operon model of the regulation of gene expression in bacteria was proposed by _____. A) Watson and Crick B) Franklin C) Darwin D) Jacob and Monod E) Mendel

D) Jacob and Monod

Why do you think that adult stem cells are found in bone marrow and the lining of the small intestine specifically? A) These are the first tissues to develop in an embryo. B) Cell division must occur in these areas indefinitely. C) This is a mystery that must be solved before use of adult stem cells is possible. D) These cells must be able to regenerate various types of cells throughout life.

D) These cells must be able to regenerate various types of cells throughout life.

In eukaryotic cells, signal transduction pathways involve __________. A) signal molecules that bind with transcription factors embedded in the plasma membrane B) signal molecules that are released from the nucleus of the target cell C) relay proteins that initiate transcription in the nucleus D) a series of relay molecules, of which the last activates a transcription factor

D) a series of relay molecules, of which the last activates a transcription factor

For the yeast Saccharomyces cerevisiae, cells of different mating types secrete factors that bind to specific receptor proteins on the cell surface of cells of the opposite mating type. This initiates a signal transduction pathway that eventually results in __________. A) transformation of the yeast from a single cell stage to a multi-cellular stage B) cell motility C) cell death D) cell fusion

D) cell fusion

Enzyme complexes that break down protein are called _____. A) lipases B) ubiquitins C) amylase D) proteasomes E) nucleases

D) proteasomes

The nuclear membrane's role in the regulation of gene expression involves _____. A) protein activation B) translation C) protein degradation D) regulating the transport of mRNA to the cytoplasm E) RNA processing

D) regulating the transport of mRNA to the cytoplasm

After translation is complete, the insulin polypeptide is activated by __________. A) alternative splicing B) the addition of a cap and tail C) the breakdown of mRNA D) the cutting of the initial translation product to yield two shorter chains joined together by sulfur linkages

D) the cutting of the initial translation product to yield two shorter chains joined together by sulfur linkages

A similar protein is found in both a bacterial cell and a single-celled eukaryote. However, the prokaryote seems to produce a much higher amount of the protein. A detailed investigation of the control mechanisms of this protein in both organisms would include a comparison of which of the following? A) identification of alternatively spliced mRNA B) mechanisms of the addition of a 5' cap C) the involvement of nuclear transport mechanisms D) the mechanisms of transcriptional control

D) the mechanisms of transcriptional control

Since the first 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) Cloned animals often develop chronic conditions that are usually only associated with old age. B) The sheep Dolly is the only mammal that has been successfully cloned. C) Cloned animals possess chromatin structure identical to that of their parent animals. D) Cloned animals are physically identical when compared to their parents.

A) Cloned animals often develop chronic conditions that are usually only associated with old age.

What controls the way in which a zygote differentiates? A) Selective genes are turned on and off, depending on the fate of the cell. B) Operons mature and control gene expression. C) The DNA of genes that will not be expressed is degraded. D) All the genes that will be expressed in the adult are made in the zygote.

A) Selective genes are turned on and off, depending on the fate of the cell.

In fruit flies, there are molecules in the egg that determine the future head and tail ends of the animal. What occurs when mRNA from the head end of an embryo is injected into the tail end of an early embryo? A) Some head structures develop at the tail end; the head end develops normally. B) The fly develops normally with no apparent changes in body plan. C) Some head structures develop at the tail end, but the head end develops abnormally as it lacks some of the mRNA molecules necessary for development. D) Some tail structures develop at the head end; the tail end develops normally.

A) Some head structures develop at the tail end; the head end develops normally

Cloning experiments with differentiated root cells from carrots revealed that __________. A) an entire plant can grow from a differentiated cell B) an entire plant can grow from an undifferentiated cell C) once cells differentiate, they can only express a specific combination of genes D) a cell from root tissue will grow new root tissue

A) an entire plant can grow from a differentiated cell

Protein-phosphorylating enzymes' role in the regulation of gene expression involves _____. A) protein activation B) translation C) protein degradation D) regulating the transport of mRNA to the cytoplasm E) RNA processing

A) protein activation

Regulatory proteins bind to _____. A) the operator B) the lactose-utilization genes C) the regulatory gene D) RNA polymerase E) transcription factors

A) the operator

A fruit fly's head-to-tail axis is established by __________. A) the position of mRNA in the egg cell B) sperm cell mRNA C) proto-oncogenes D) homeotic genes

A) the position of mRNA in the egg cell

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 role of transcription factors B) histones C) enhancers D) the action of DNA polymerase

A) the role of transcription factors

The Rb protein prevents mitosis by inhibiting cells from entering S phase. Human papillomavirus (HPV) is thought to inhibit the action of the Rb protein in cervical epithelial cells. What would be the effect of cervical cells being infected with HPV? A) The number of cells in the G1 phase of the cell cycle would increase. B) The mitotic rate would increase. C) The mutation rate would decrease. D) The growth of cervical cells would decrease.

B) The mitotic rate would increase.

It is possible for a cell to make proteins that last for months; for example, hemoglobin in red blood cells. However, many proteins are short-lived and may be degraded in days or even hours. Why do cells make proteins with such a short life? A) Most cells in the body live only a few days. B) This enables cells to control the amount of protein present. C) Most proteins are used only once. D) Only cancer cells, which can keep dividing, contain long-lasting proteins

B) This enables cells to control the amount of protein present.

Alternative RNA splicing has revealed inaccuracies in the one gene-one polypeptide hypothesis. Why? A) It really should be the one intron: one polypeptide hypothesis. B) Transcription of the same gene can lead to the production of different mRNAs and therefore different proteins. C) It shows that it takes more than one gene to code for most polypeptides. D) It really should be the one exon: one polypeptide hypothesis.

B) Transcription of the same gene can lead to the production of different mRNAs and therefore different proteins.

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) alternative RNA splicing B) X chromosome inactivation C) a mutation D) a homeotic gene

B) X chromosome inactivation

Which of the following would be most likely to lead to cancer? A) failure of both a proto-oncogene that promotes cell division and a tumor-suppressor gene to produce proteins B) generation of multiple copies of a proto-oncogene that promotes cell division and inactivation of a tumor-suppressor gene C) failure of a proto-oncogene that promotes cell division to produce a protein and generation of multiple copies of a tumor-suppressor gene D) generation of multiple copies of a proto-oncogene that promotes cell division and activation of a tumor-suppressor gene

B) generation of multiple copies of a proto-oncogene that promotes cell division and inactivation of a tumor-suppressor gene

A signal transduction pathway activates a transcription factor that responds by __________. A) activating an inactive enzyme B) initiating mRNA synthesis C) altering the cytoskeleton D) changing the chemical composition of the cytosolic environment

B) initiating mRNA synthesis

Stem cells could be immensely important in the treatment of which of the following conditions in the near future? A) lung cancer B) spinal cord injuries C) loss of a limb D) hardened arteries

B) spinal cord injuries

A mutation in the ras gene can __________. A) alter the number of copies of the ras gene B) stimulate cell division C) control cell division D) inhibit cell division

B) stimulate cell division

A mutation in the operator region of the trp operon can prevent the trp repressor from binding to this operator. When these mutant cells are placed in a solution containing chicken broth, which of the following events would happen? A) The repressor would bind to the operator irrespective of the presence of amino acids in the environment. B) The transcription of the trp operon would be inhibited. C) Tryptophan would bind to the repressor. D) The transcription of the repressor protein is inhibited.

C) Tryptophan would bind to the repressor.

MicroRNA (miRNA) functions by binding to __________ and blocking translation. A) tRNA molecules B) the ribosome C) complementary mRNA sequences D) introns

C) complementary mRNA sequences

What is the function of a spliceosome? A) protein activation B) translation C) protein degradation D) regulating the transport of mRNA to the cytoplasm E) RNA processing

E) RNA processing

Colonoscopy is the examination of the large colon. It allows for visual diagnosis of ulcers and polyps, which may lead to colon cancer. A polyp _____. A) causes mutations that lead to colon cancer B) is a malignant tumor C) is a cluster of abnormal cells D) is likely to form after one exposure to a carcinogen

C) is a cluster of abnormal cells

In frogs, when the nucleus of an intestinal cell of a tadpole is transferred to an egg whose nucleus has been removed (nuclear transplantation), some of the eggs will develop into normal tadpoles. This demonstrates that _____. A) these cells could not dedifferentiate B) frogs have adult stem cells C) these cells have retained all of their genetic potential D) intestinal cells are not differentiated

C) these cells have retained all of their genetic potential