BIOL 1030 Chapter 11 Homework Questions

Which of these is NOT a component of the lac operon? lactose-utilization genes only promoter only regulatory gene only operator only promoter and operator

regulatory gene only

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) Tryptophan would bind to the repressor. B) The transcription of the trp operon would be inhibited. C) The repressor would bind to the operator irrespective of the presence of amino acids in the environment. D) The transcription of the repressor protein is inhibited.

Tryptophan would bind to the repressor.

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 __________. X chromosome inactivation a mutation alternative RNA splicing a homeotic gene

X chromosome inactivation

Which of these is NOT a carcinogen? cigarette smoke fat UV light testosterone all of the above are carcinogens

all of the above are carcinogens

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

complementary mRNA sequences

A(n) ____ is a protein that promotes cell division. In excess, such a protein may lead to cancer

growth factor

In the presence of a regulatory protein the lac operon is _____. transcribed not transcribed transcribed at a faster than usual rate is turned on either transcribed or not transcribed

not transcribed

A gene that causes a cell to become cancerous is called a(n) ___

oncogene

Enzyme complexes that break down protein are called _____. lipases ubiquitins amylase proteasomes nucleases

proteasomes

Protein-phosphorylating enzymes' role in the regulation of gene expression involves ___ protein activation translation protein degradation regulating the transport of mRNA to the cytoplasm RNA processing

protein activation

A normal gene that, if mutated, can lead to cancer is called a(n) ___

proto-oncogene

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

regulating the transport of mRNA to the cytoplasm

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

spinal cord injuries

A mutation in the ras gene can _____ inhibit cell division alter the number of copies of the ras gene stimulate cell division control cell division

stimulate cell division

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

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? identification of alternatively spliced mRNA mechanisms of the addition of a 5' cap the mechanisms of transcriptional control the involvement of nuclear transport mechanisms

the mechanisms of transcriptional control

Regulatory proteins bind to _____. the operator the lactose-utilization genes the regulatory gene RNA polymerase transcription factors

the operator

___ bind(s) to DNA enhancer regions. RNA polymerase Promoters Introns Activators Exons

Activators

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) Cloned animals possess chromatin structure identical to that of their parent animals. C) Cloned animals are physically identical when compared to their parents. D) The sheep Dolly is the only mammal that has been successfully cloned.

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

The operon model of the regulation of gene expression in bacteria was proposed by _____. Watson and Crick Franklin Darwin Jacob and Monod Mendel

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) This is a mystery that must be solved before use of adult stem cells is possible. B) These are the first tissues to develop in an embryo. C) Cell division must occur in these areas indefinitely. D) These cells must be able to regenerate various types of cells throughout life.

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

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? The mitotic rate would increase. The growth of cervical cells would decrease. The number of cells in the G1 phase of the cell cycle would increase. The mutation rate would decrease.

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) Only cancer cells, which can keep dividing, contain long-lasting proteins. B) Most proteins are used only once. C) This enables cells to control the amount of protein present. D) Most cells in the body live only a few days.

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 shows that it takes more than one gene to code for most polypeptides B) It really should be the one intron: one polypeptide hypothesis. C) Transcription of the same gene can lead to the production of different mRNAs and therefore different proteins. D) It really should be the one exon: one polypeptide hypothesis.

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

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 _____. histones enhancers the role of transcription factors the action of DNA polymerase

the role of transcription factors

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 __ these cells could not dedifferentiate intestinal cells are not differentiated frogs have adult stem cells these cells have retained all of their genetic potential

these cells have retained all of their genetic potential