Med Gen chap 12 & 7
A woman whose brother is affected by hemophilia (X-linked) may choose to undergo ________ before having children to determine whether she inherited the defective factor VIII allele from her mother. a. carrier testing b. prenatal testing c. newborn genetic screening d. preimplantation genetic diagnosis e. amniocentesis
A
By sequencing the genomes of cancer cells, researchers learned that cancer cells contain ________. a. more mutations than previously thought b. the same types of mutations in different cancer types c. about the same number of mutations as predicted d. less mutations than previously thought e. translocations, but not missense mutations
A
Expression of the XIST gene in female mammals is responsible for ________. a. formation of a Barr body b. mosaicism in males c. reversible X inactivation in females d. expression of the X inactivation center e. death of the cell
A
In humans, body size, muscle mass, and patterns of fat distribution are types of ____ sex characteristics. a. secondary b. tertiary c. initial d. primary e. mutable
A
In order for a fetus to develop female reproductive organs, ________. a. SRY must be absent b. AMH must be present c. testosterone must be present d. Mullerian ducts must be absent e. SRY must be present
A
Stem cells ____. a. have the property of self-renewal by division b. are immature cells that become nerve tissue susceptible to cancer c. do not have the ability to divide d. are found only in cancerous tumors e. are the least likely to give rise to cancer
A
The RB1 tumor-suppressor gene ____. a. controls the G1/S checkpoint b. is overactive in cases of leukemia c. is overactive in cases of retinoblastoma d. controls the G2/M checkpoint e. is overactive in cases of breast cancer
A
The presence of a mane of hair on male lions, and its absence in female lions, is an example of a(n) ________. a. sex-limited trait b. imprinted gene c. X-linked trait d. inactivated gene e. sex-influenced trait
A
The ras proto-oncogene family encodes proteins that function in ________, relaying signals from outside the cell across the cell membrane. a. signal transduction b. tumor suppression c. DNA mutation d. protein folding e. metastasis
A
The specific translocation forming the Philadelphia chromosome leads to chronic myelogenous leukemia because ________, resulting in continuous cell division. a. the BCR gene sequences "switch on" the ABL1 sequences b. the ABL1 gene sequences "switch on" the BCR sequences c. the cells become polyploid d. the cells become aneuploid e. the BCR gene sequences "switch off" the ABL1 allele
A
The translocation seen in the Philadelphia chromosome in myelogenous leukemia represents ____. a. a specific chromosomal aberration accompanying a specific cancer b. a chromosomal aberration that is secondary to the cancer c. a proto-oncogene that has been deleted from chromosome 6 and inserted into chromosome 7 d. a chromosomal aberration that is caused by the development of cancer e. the evidence of exposure to chemical carcinogens
A
What is an advantage of exon skipping? a. The precise mutation present in a given patient can be targeted for correction. b. The genetic defect can't be passed onto future generations. c. Viruses are used to deliver the normal gene to affected cells. d. Antisense oligonucleotides deliver the functional gene to the affected cells. e. Exons are spliced out of nonfunctional genes.
A
________ occur(s) when cancer cells migrate away from the primary tumor and form new malignant tumors in other parts of the body. a. Metastasis b. Cell division c. Malignancy d. Cloning e. Mutations
A
A characteristic of all cancers is that ____. a. the rapid proliferation of cells is required b. the cells divide continuously c. they are always due to a chromosome disjunction mutation d. they have a benign form and a deadly form e. several mutations in several different genes are required in order for cancer to develop
B
Cancer therapies such as Gleevec and Herceptin may be preferable to traditional therapies that use radiation and chemicals because these new therapies ________. a. can treat several different cancer types b. target only cancer cells c. target all dividing somatic cells d. prevent the inheritance of cancer-causing alleles e. remove excess methylation from DNA repair genes
B
Exposure to ________ increases the risk for developing lung cancer, which causes 30% of all cancer deaths in the US. a. UV radiation b. all tobacco products c. the human papilloma virus d. cigarettes, but not chewing tobacco e. Gardasil
B
If a cell begins to divide in an uncontrolled way, it ____. a. is a sign of metastasis b. may form a benign tumor c. signals uncontrolled cell division in other parts of the body d. will always form a cancerous tumor e. is considered a malignant tumor
B
If genetic testing reveals the presence of a breast cancer allele in Anna's mother, but not her maternal aunts, then Anna ________. a. should not seek genetic counseling b. may have inherited this allele from her mother c. will develop breast cancer at a young age d. did not inherit this allele from her mother e. should not be tested for these breast cancer alleles
B
The most common vectors used in DNA therapy experiments are _____. a. naked DNA b. retroviruses and adenoviruses c. modified human cells d. antisense oligonucleotides (AONs) e. bacteria
B
When six or more mutations in the FAP gene occur in a specific sequence in a certain cell, the result is ________. a. polyp b. colon cancer c. intermediate adenoma d. late adenoma e. normal epithelium
B
All cancers have ________. a. normal chromosomal structures b. genomic stability c. higher rates of mutation than normal cells d. mutant oncogenes e. normal numbers of chromosomes
C
An individual who is at risk of passing a genetic defect onto his or her offspring would most likely undergo ____. a. enzyme replacement therapy b. preimplantation genetic diagnosis (PGD) c. genetic testing d. genetic screening e. amniocentesis
C
Gene therapy for muscular dystrophy, a degenerative disorder caused by mutations in the dystrophin gene, would be performed ________ by introducing a normal dystrophin gene into the patient's ________. a. ex vivo; embryonic stem cells b. in vivo; embryonic stem cells c. in vivo; muscle tissue d. in vivo; bone marrow e. ex vivo; muscle tissue
C
In most cases, cancer-causing mutations ____. a. occur during the G0 phase of the cell cycle b. metastasize within a short time c. accumulate over a number of years d. accumulate very quickly within a single cell e. must all occur on the q arm of a chromosome
C
Many specialized cells, such as white blood cells, ____. a. mutate into other cell types by signals from bone marrow cells b. skip anaphase in order to avoid the high likelihood of mutation during this phase of mitosis c. remain in G0 until stimulated by external signals to reenter the cell cycle and divide d. divide continuously and never transition to G0 e. remain in S until hormonal signals cause the cell to reenter the cell cycle and divide
C
Mutant BRCA1 and BRCA2 alleles ________. a. increase the number of chromosomes in the cell b. function at the G2/M cell cycle checkpoint c. increase the risk of breast and ovarian cancer d. decrease the risk of breast and ovarian cancer e. are proto-oncogenes
C
Pattern baldness is a(n) ____ trait. a. sex-linked b. sex-limited c. sex-influenced d. Y-linked e. X-linked
C
The Barr body is present in the cells of female mammals and indicates the ________. a. inactive Y chromosome b. XX female genotype c. inactive X chromosome d. active Y chromosome e. active X chromosome
C
The field of epigenetics has opened the way for the development of a new class of anticancer drugs ____. a. that stop mutations before they occur in individuals with a predisposition to certain kinds of cancer b. that increase the level of methylation in cancer cells c. because of the discovery that epigenetic modification of key genes is important in some cancers and the fact that epigenetic changes are reversible d. that are very similar to many chemotherapy treatments but are much more targeted and effective e. used specifically to treat breast cancer because the key genes involved in this cancer cannot be epigenetically modified
C
The protein product of the p53 gene functions at the G1/S cell cycle checkpoint, pausing the cell cycle if DNA damage occurs; therefore, p53 is a(n) ________. a. example of loss of heterozygosity b. oncogene c. tumor suppressor gene d. signal transduction pathway e. proto-oncogene
C
The temperature at which eggs are incubated determines the sex of the offspring in ________. a. humans b. insects c. some reptiles d. mammals e. some birds
C
The undifferentiated genitalia of an early human embryo develops into male genitalia under the influence of ____. a. Wolfian duct inhibitors b. prolactin c. testosterone, AMH, and DHT d. oxytocin e. prostaglandin and DHT
C
A Barr body is a(n) ____. a. immature trophoblast b. mature blastocyst c. immature blastocyst d. inactivated X chromosome e. activated X chromosome
D
A proto-oncogene ____. a. encodes tumor-suppressing proteins b. always becomes cancerous c. repairs DNA d. regulates cell division e. causes cancer
D
According to the American Cancer Society, 30% of all cancer deaths in the U.S. are due to ____. a. ultraviolet light exposure b. pesticide and herbicide exposure c. automobile exhaust d. smoking e. industrial pollutants
D
Cancer-causing mutations of the cell cycle ____. a. eliminate one or more stages of the cycle b. increase the speed of the cycle c. stop the cycle and cause a build-up of cell toxins d. cause the cell to bypass checkpoints in the cycle e. interfere with S phase of the cycle
D
During metabolism, cancer-causing ____ are generated. a. methyl amines b. mutated tRNA fragments c. BRCA1 genes d. reactive oxygen species (ROS) e. BCR-ABL proteins
D
Hereditary nonpolyposis colon cancers (HNPCC) ____. a. are rare in the United States, but common in Europe b. are caused by one-of-a-kind DNA sequences called microsatellites c. are caused by one mutation in a single gene d. are caused by several mutations in several different genes e. begin with a mutation in the APC gene
D
In the United States, all babies are checked for PKU at birth as part of routine ________. a. prenatal testing b. pedigree analysis c. preimplantation genetic diagnosis d. genetic screening e. genetic testing
D
Individuals with complete androgen insensitivity are phenotypically female because they ________. a. have two X chromosomes b. have testes c. lack testes and testosterone d. lack functional androgen receptors and cannot respond to testosterone e. have functional female reproductive organs and cannot respond to androgen
D
Sex-influenced traits are expressed ____. a. more in males than in females b. only in females c. only in males d. as a result of hormone differences between males and females e. after the formation of a Barr body
D
________ is defined as the transfer of genes into the gametes; such genetic modification could then be inherited by all future offspring. a. Enhancement gene therapy b. Somatic gene therapy c. Enzyme replacement therapy d. Germ-line gene therapy e. Gene doping
D
Aberrant DNA methylation can lead to cancer because ________. a. methylation is not present in normal cells b. the Philadelphia chromosome is caused by demethylation c. imprinting is prevented d. hypomethylation can activate key growth control genes e. hypermethylation can inactivate DNA repair genes
E
About ____ of all cancer cases have a hereditary component. a. 25% to 35% b. 1% to 3% c. 10% to 15% d. 15% to 20% e. 5% to 10%
E
According to the Lyon hypothesis ________. a. the same X chromosome is inactivated in each cell b. one X chromosome is inactivated in males c. X inactivation occurs at puberty d. females have more X-linked genes than males e. female mammals are mosaics due to X chromosome inactivation
E
During the M checkpoint, the cell ____. a. proceeds to interphase and completes DNA replication b. proceeds to S phase or enters inactive G0 state c. monitors completion of DNA synthesis and DNA damage d. proceeds to G2 phase and the cell prepares to divide e. monitors attachment of spindle fibers to chromosomes
E
In an XX embryo, ____ inactivation of one X chromosome usually occurs when the embryo has about 32 cells. a. phenotypic b. selective c. inhibited d. cascading e. random
E
The ________ cell cycle checkpoint ensures that DNA replication has occurred accurately. a. epithelial b. G1/S c. M d. G0 e. G2/M
E
There will always be a baseline rate of cancer because ________. a. most tumors are benign b. all cancer mutations are inherited c. cancer is contagious d. pollution causes cancer e. all cancers are ultimately caused by mutations
E
When an individual is heterozygous for a cancer-related allele, s/he may develop cancer after mutation of the other, normal allele, a concept known as ________. a. accumulation of mutations with age b. cell division c. chromosomal mutations d. metastasis e. loss of heterozygosity
E
Which scenario describes a situation for which genetic counseling is recommended? a. Couples who have undergone IVF b. Women who have had one miscarriage, and no other pregnancies c. Women under age 35 who plan to become pregnant d. Couples who have no family history of genetic disorders e. Couples who already have a child with a birth defect
E
_____ is performed to detect genetic disorders and birth defects in a fetus. a. Enzyme replacement therapy b. Genetic screening c. Gene therapy d. Carrier testing e. Prenatal testing
E
________ is performed on early embryos to test for the presence of genetic defects; this technology can also be used to select for umbilical cord stem cell donors called ________. a. Chorionic villus sampling; surrogates b. Amniocentesis; egg donor surrogates c. Gamete intra-fallopian transfer; test tube babies d. Polar body biopsy; savior babies e. Preimplantation genetic diagnosis; savior babies
E
In rapidly dividing cells, expression of BRCA1 and BRCA2 genes is the highest during the ____. a. G2/mitosis transition b. metaphase to anaphase transition c. S/G2 transition d. mitosis to cytokinesis transition e. G1/S transition and into S phase
E