CellBio Chp 11

Lac operon regulatory genes are _____.

A mistake during DNA replication prevents the trp repressor from binding to the operon operator. When these cells are placed in a solution containing chicken broth, what happens

What controls the way in which a zygote differentiates?

When are DNA molecules the least tightly coiled?

Anhidrotic ectodermal dysplasia is an X-linked disorder that results in the absence of sweat glands. How would this condition be manifested in a heterozygous female?

In eukaryotic cells, several proteins are involved in the process of transcription. This process involves enhancers that are _____

Alternative RNA splicing has revealed inaccuracies in the one gene-one polypeptide hypothesis. Why?

MicroRNA (miRNA) controls _____.

Microtubules in the cytoplasm of the cell are composed of two protein subunits, α-tubulin and β-tubulin. Addition of colchicine to the cells results in the disassembly of the microtubules and consequently an increase in the concentration of tubulin subunits. Based on your knowledge of translational regulation, what changes in protein production would occur?

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 which of the following experiments?

In embryonic mice, a homeotic gene controls development of the neck, which includes the larynx and thymus. If this gene were deleted, a full-term mouse would show _____.

A researcher performs a DNA microarray but forgets to add the enzyme reverse transcriptase. This is important because the enzyme makes _____ from a(n) _____ template.

In eukaryotic cells, signal transduction pathways involve _____.

Steward's experiment with carrot cells revealed that _____.

Using nuclear transplantation, it is possible to generate _____ for therapeutic uses.

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?

Stem cells could be immensely important in the treatment of which of the following conditions?

Proto-oncogenes have the potential to become oncogenes. Which of the following is most likely to lead to cancer?

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?

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 mutation in the ras gene can _____.

Which of the following cell types would most likely have a high rate of error in DNA replication and consequently a rapid mutation rate?

Which of the following molecules would bind to an operator?

In E. coli, the operon that controls lactose-utilization genes consists of _____.

In order to function as specialized cells, your muscle and bone cells undergo significant changes in gene regulation. This is because _____.

The female calico cat has a particular coat coloring because each cell contains _____ active X chromosome(s)

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 complex?

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?

In fruit flies, there are molecules in the egg that determine the body layout of the adult fly. What occurs when mRNA from the head end of an embryo is injected into the tail end of an early embryo?

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?

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?

Stem cells could be immensely important in the treatment of which of the following conditions?

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 these genes?

Tobacco causes more cases and types of cancer than any other single agent. In individuals who inhale tobacco smoke, lung cancer is the most prevalent form of cancer. What form of cancer is second to lung cancer in estimated number of cases for this risk factor?

In prokaryotes, a group of genes with related functions is called _____.

Tryptophan is placed into a culture of E. coli cells. As a result, the bacterial cells switch off transcription of tryptophan because the amino acid binds to the _____.

The promoter of an operon _____.

In prokaryotes, operons _____.

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 they produce human growth factor?

In E. coli the lactose operon (lac operon) is turned on in the presence of _____.

In some species of bacteria that are resistant to the antibiotic tetracycline, the antibiotic molecule attaches to a repressor protein. This prevents binding of the repressor to the bacterial DNA and allows a set of genes to be transcribed. The transcription of these genes is under the control of a(n) _____

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 _____.

Operons _____.

In multicellular eukaryotic cells, the control of gene expression is more complex because _____

Cells become specialized by a process known as _____

Histones are _____.

In eukaryotes, DNA packing seems to affect gene expression primarily by _____.

In eukaryotes, chromosomes are tightly coiled due to the association of histone proteins and DNA. These structures are known as _____

Nucleosomes _____.

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 _____

The DNA-histone complexes that are formed in eukaryotic cells directly inhibit _____.

Enhancers are _____.

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 _____.

Eukaryotes have the ability to switch gene expression on or off. If a repressor protein binds to a DNA sequence called a(n) _____, it may block gene expression.

In eukaryotes, gene expression is regulated mostly by _____.

Which of the following is true of gene regulation in both eukaryotes and prokaryotes?

MicroRNA (miRNA) functions by binding to _____ and blocking translation.

Gene expression can also be controlled after the mRNA molecule has left the nucleus. These mechanisms may include the _____

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 scientist is investigating a new drug that blocks the action of the enzyme responsible for splicing mRNA molecules. If this drug is effective, which of the following statements will be true?

An animal's head-to-tail axis is established by _____

DNA microarrays are useful tools for studying _____.

A signal transduction pathway activates a transcription factor that responds by _____.

Some glucose transport molecules are controlled by levels of insulin. When insulin binds to a specific _____, the signal is relayed to a(n) _____ , which then controls gene expression.

Clones are derived _____

Experiments involving _____ have demonstrated that differentiated cells contain all of the genetic information found in undifferentiated 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 _____.

Researchers successfully cloned Dolly the sheep, proving that cloning an adult animal cell can be successful. This type of cloning is known as _____

Why do you think that adult stem cells are found in bone marrow and the lining of the small intestine specifically?

Embryonic stem cells differ from adult stem cells because they _____

Which of the following statements best describes cancer cells?

Which of the following would be most likely to lead to cancer?

In human cells, oncogenes _____.

Which of the following genes inhibit cell division?

A cancer cell _____.

Most human cancers are _____.

The p53 protein _____.

In humans, most cancers are caused by _____.

The leading cause of death in the United States is _____.