A temperature-sensitive mutant allele of Ras causes the Ras protein to be fixed in the GDP-bound state at the nonpermissive temperature. What phenotype would you expect a cell homozygous for this mutation to have at the nonpermissive temperature? A.)  It would stop dividing. B.) It would divide continuously. C.) It would divide normally.

The cystic fibrosis gene encodes a chloride channel protein necessary for normal cellular functions. Let us assume that if at least 5% normal channels are present, the affected individual has mild symptoms of cystic fibrosis. Having less than 5% normal channels produces severe symptoms. At least 50% of the channels must be expressed for the individual to be phenotypically normal. This gene has various mutant recessive alleles: Predict the percent of functional channels and severity of symptoms for the following genotypes: a. heterozygous for CF100 b. homozygous for CF100 c. heterozygous, with one copy of CF100 and one of CF3 d. heterozygous, with one copy of CF1 and one copy of CF3

INTERPRET DATA Develop a simple hypothesis that would explain the behavior of each of the following types of mutants in E. coli. Mutant a: The map position of this mutation is in the trp operon. The mutant cells are constitutive; that is, they produce all the enzymes coded for by the trp operon, even if large amounts of tryptophan are present in the growth medium. Mutant b: The map position of this mutation is in the trp operon. The mutant cells do not produce any enzymes coded for by the trp operon under any conditions. Mutant c: The map position of this mutation is some distance from the trp operon. The mutant cells are constitutive; that is, they produce all the enzymes coded for by the trp operon, even if the growth medium contains large amounts of tryptophan.

What are the roles of cellular proto-oncogenes, and how are these roles consistent with their implication in oncogenesis?

Who Owns Your Genome? John Moore, an engineer working on the Alaska oil pipeline, was diagnosed in the mid-1970s with a rare and fatal form of cancer known as hairy cell leukemia. This disease causes overproduction of one type of white blood cell known as a T lymphocyte. Moore went to the UCLA Medical Center for treatment and was examined by Dr. David Golde, who recommended that Moores spleen be removed in an attempt to slow down or stop the cancer. For the next 8 years, John Moore returned to UCLA for checkups. Unknown to Moore, Dr. Golde and his research assistant applied for and received a patent on a cell line and products of that cell line derived from Moores spleen. The cell line, named Mo, produced a protein that stimulates the growth of two types of blood cells that are important in identifying and killing cancer cells. Arrangements were made with Genetics Institute, a small start-up company, and then Sandoz Pharmaceuticals, to develop the cell line and produce the growth-stimulating protein. Moore found out about the cell line and its related patents and filed suit to claim ownership of his cells and asked for a share of the profits derived from the sale of the cells or products from the cells. Eventually, the case went through three courts, and in July 1990n years after the case beganthe California Supreme Court ruled that patients such as John Moore do not have property rights over any cells or tissues removed from their bodies that are used later to develop drugs or other commercial products. This case was the first in the nation to establish a legal precedent for the commercial development and use of human tissue. The National Organ Transplant Act of 1984 prevents the sale of human organs. Current laws allow the sale of human tissues and cells but do not define ownership interests of donors. Questions originally raised in the Moore case remain largely unresolved in laws and public policy. These questions are being raised in many other cases as well. Who owns fetal and adult stem-cell lines established from donors, and who has ownership of and a commercial interest in diagnostic tests developed through cell and tissue donations by affected individuals? Who benefits from new genetic technologies based on molecules, cells, or tissues contributed by patients? Are these financial, medical, and ethical benefits being distributed fairly? What can be done to ensure that risks and benefits are distributed in an equitable manner? Gaps between technology, laws, and public policy developed with the advent of recombinant DNA technology in the 1970s, and in the intervening decades, those gaps have not been closed. These controversies are likely to continue as new developments in technology continue to outpace social consensus about their use. Should the physicians at UCLA have told Mr. Moore that his cells and its products were being commercially developed?

Who Owns Your Genome? John Moore, an engineer working on the Alaska oil pipeline, was diagnosed in the mid-1970s with a rare and fatal form of cancer known as hairy cell leukemia. This disease causes overproduction of one type of white blood cell known as a T lymphocyte. Moore went to the UCLA Medical Center for treatment and was examined by Dr. David Golde, who recommended that Moores spleen be removed in an attempt to slow down or stop the cancer. For the next 8 years, John Moore returned to UCLA for checkups. Unknown to Moore, Dr. Golde and his research assistant applied for and received a patent on a cell line and products of that cell line derived from Moores spleen. The cell line, named Mo, produced a protein that stimulates the growth of two types of blood cells that are important in identifying and killing cancer cells. Arrangements were made with Genetics Institute, a small start-up company, and then Sandoz Pharmaceuticals, to develop the cell line and produce the growth-stimulating protein. Moore found out about the cell line and its related patents and filed suit to claim ownership of his cells and asked for a share of the profits derived from the sale of the cells or products from the cells. Eventually, the case went through three courts, and in July 1990n years after the case beganthe California Supreme Court ruled that patients such as John Moore do not have property rights over any cells or tissues removed from their bodies that are used later to develop drugs or other commercial products. This case was the first in the nation to establish a legal precedent for the commercial development and use of human tissue. The National Organ Transplant Act of 1984 prevents the sale of human organs. Current laws allow the sale of human tissues and cells but do not define ownership interests of donors. Questions originally raised in the Moore case remain largely unresolved in laws and public policy. These questions are being raised in many other cases as well. Who owns fetal and adult stem-cell lines established from donors, and who has ownership of and a commercial interest in diagnostic tests developed through cell and tissue donations by affected individuals? Who benefits from new genetic technologies based on molecules, cells, or tissues contributed by patients? Are these financial, medical, and ethical benefits being distributed fairly? What can be done to ensure that risks and benefits are distributed in an equitable manner? Gaps between technology, laws, and public policy developed with the advent of recombinant DNA technology in the 1970s, and in the intervening decades, those gaps have not been closed. These controversies are likely to continue as new developments in technology continue to outpace social consensus about their use. Do you think that donors or patients who provide cells and/or tissues should retain ownership of their body parts or should share in any financial benefits that might derive from their use in research or commercial applications?

Control of gene expression in eukaryotic cells occurs at which level(s)? a. only the transcriptional level b. epigenetic and transcriptional levels c. epigenetic, transcriptional, and translational levels d. epigenetic, transcriptional, post-transcriptional, translational, and post-translational levels

In selecting target cells to receive a transferred gene in gene therapy, what factors do you think would have to be taken into account?

Through alternative splicing, eukaryotes (a) reinforce gene inactivation (b) prevent transcription of heterochromatin (c) produce related but different proteins in different tissues (d) amplify genes to meet the requirement of high levels of a gene product (e) bind transcription factors to enhancers to activate transcription

A region on chromosome 6 has been linked to schizophrenia, but researchers have not found a specific gene associated with this disease. What steps would be necessary to locate the gene?