Choose the best answer.

1		Most human traits are influenced by both genetic and environmental factors.
			A)	True
			B)	False
2		Which of these factors does not provide evidence that the disorder may have a genetic cause?
			A)	An increased frequency of the disorder in genetic relatives of an affected individual than in the general population.
			B)	A higher concordance in identical twins than in fraternal twins.
			C)	Individuals that live with an affected individual are more likely to also exhibit the disorder.
			D)	All of these indicate a genetic cause.
			E)	None of these indicate a genetic cause.
3		Which of these statements would indicate that the trait in question has a genetic component?
			A)	Several adopted individuals living in the same family all have exceptionally strong fingernails.
			B)	In the last two weeks, every child at your daughter's daycare has had a cold.
			C)	Your brother, two cousins, and a great uncle all have been diagnosed with Duchenne muscular dystrophy, a disorder that affects about 1/7000 individuals.
			D)	All of these indicate a genetic component.
			E)	None of these indicate a genetic component.
4		Identification of a genetic disorder in a model species allows analysis of that disorder that can then be applied to humans.
			A)	True
			B)	False
5		Alteration of gene sequences in individuals affected by genetic disease:
			A)	Demonstrates the importance of environmental factors affecting disease expression.
			B)	Can be demonstrated by gene cloning and DNA sequencing.
			C)	Are the first line of evidence pursued to determine if the disease is in fact genetic.
			D)	All of these.
			E)	None of these.
6		Which of these characteristics of Tay-Sachs indicates that it is likely to be genetic?
			A)	The frequency of the disorder is approximately 1/3,600 in the Ashenazi Jewish population, but much less common in other Caucasian populations.
			B)	The disorder leads to death at a very young age.
			C)	Tay-Sachs often appears in a pedigree with no known family history of the disorder.
			D)	All of these.
			E)	None of these.
7		Which of the following observations is most conclusive that Gaucher disease is inherited in an autosomal recessive pattern? (All these observations are of a single family, who all live together).
			A)	Brothers David and Joshua are both affected with Gaucher disease.
			B)	Mom has no family history of Gaucher disease.
			C)	Mom and Dad are both unaffected with Gaucher disease.
			D)	The boys experience different severities of the disease.
			E)	None of these indicate an autosomal recessive pattern.
8		Which of the following would be most likely to be inherited in an autosomal recessive pattern in humans?
			A)	A mutant gene has a new function that creates a phenotype.
			B)	A deletion on the X chromosome inactivates a gene.
			C)	A point mutation in a regulatory element reduces the level of gene expression of a gene on chromosome 12.
			D)	None of these.
9		Jeremy's grandfather, uncle, and sister all have been diagnosed with the same genetic disorder. The most likely pattern of inheritance for this disorder is:
			A)	Autosomal dominant, since it is present in all three generations.
			B)	Autosomal recessive, since Jeremy's parents are unaffected.
			C)	X-linked recessive, since it affects more males than females.
			D)	You cannot determine the pattern of inheritance from this information.
10		For most dominant genetic diseases, homozygous dominant individuals are more severely affected than those that are heterozygous.
			A)	True
			B)	False
11		Why are males more likely to exhibit an X linked recessive trait than females?
			A)	Most genes on the X chromosome are not shared with the Y.
			B)	Male sex hormones affect expression of genes from the X chromosome.
			C)	X linked traits tend to control male secondary sexual development.
			D)	All of these.
			E)	None of these.
12		A couple comes to your genetic counseling clinic concerned that they might have a second child affected with the same X-linked recessive disease displayed by their son. Neither of the parents displays the trait. What do you tell them?
			A)	They have a ¼ chance of having another affected chilD. Since it's a recessive trait, they must both be carriers.
			B)	They have a ¼ chance of having another affected child but only if the child is a boy. They could try to select "girl" sperm to avoid the disease.
			C)	They have a ½ chance of having another affected child, but only if the child is a girl. They could try to select "boy" sperm to avoid the disease.
			D)	They are not at risk of having another affected child.
13		Genetic heterogeneity could be described as:
			A)	A population in which there are several mutant alleles for a specific gene.
			B)	A situation where different alleles of a gene cause different severity of disease.
			C)	A situation where people with the same genotype might have different phenotypes.
			D)	A situation where people with the same phenotype have different genotypes.
14		You are certain to know someone who has undergone genetic testing.
			A)	True
			B)	False
15		Which of these could be considered a genetic test?
			A)	A midwife licks the newborn's forehead to see if it tastes salty. If it does, she suggests to the family that the child may have cystic fibrosis.
			B)	A man of Ashkenazi Jewish descent submits a tissue sample to determine if his level of protein produced by the gene affected in Gaucher disease is normal or reduced.
			C)	An African American woman submits a DNA sample to find out if she is a carrier for the allele that causes sickle cell anemia.
			D)	All of these.
			E)	None of these.
16		Prenatal genetic testing requires collection of fetal cells, usually by amniocentesis or chorionic villus sampling.
			A)	True
			B)	False
17		Which definition of cancer is the most accurate?
			A)	A group of diseases characterized by uncontrolled cell division.
			B)	A disorder in which cells produce a localized tumor.
			C)	A disorder in which tissues of the body are replaced by nonfunctional cells.
			D)	All of these.
			E)	None of these.
18		Genes which promote cancer are called:
			A)	Tumor suppressors.
			B)	Oncogenes.
			C)	Growth factors.
			D)	Malignancy enhancers.
19		The first oncogene to be identified:
			A)	Was c-src.
			B)	Causes sarcomas in chickens.
			C)	Is normally expressed at high levels in eukaryotic cells.
			D)	All of these.
			E)	None of these.
20		Rous sarcoma virus (RSV) causes cancer by integrating into genes that normally control cell division and eliminating their function.
			A)	True
			B)	False
21		When a cell is stimulated by a growth hormone:
			A)	The presence of the hormone directly activates gene expression.
			B)	A cascade of protein interactions leads to changes in gene expression.
			C)	Cell surface receptors are deactivated.
			D)	All of these.
			E)	None of these.
22		Activation of a cell signaling pathway in absence of a growth factor signal can lead to uncontrolled cell division.
			A)	True
			B)	False
23		Which of these would be likely to lead to oncogenesis?
			A)	Reduced levels of function of a repressor of cell division.
			B)	A mutation that causes the growth hormone receptor to be constitutively active.
			C)	A mutation that prevents activated Ras from being deactivated.
			D)	All of these.
			E)	None of these.
24		Genetic changes that can convert proto-oncogenes to oncogenes include all of the following EXCEPT:
			A)	Point mutations.
			B)	Increase in the copy number of the proto-oncogene.
			C)	A change in the relationship between a coding region and regulatory elements.
			D)	Deletion of the proto-oncogene.
			E)	All of these can convert proto-oncogenes to oncogenes.
25		The breakpoints in the bcr and abl genes that lead to translocation and creation of the Philadelphia chromosome demonstrate an unusually high level of chromosome breakage.
			A)	True
			B)	False
26		Which of these factors might influence the creation of translocations known to cause chronic myelogenous leukemia (the Philadelphia chromosome) and Burkitt's lymphoma?
			A)	The sites of translocation show a lower frequency of breakage than other chromosomal sites.
			B)	Sites on non-homologous chromosomes may have enough similarity of sequence to stimulate "semi-homologous" recombination.
			C)	Sister chromatid exchange can occur during mitosis.
			D)	All of these.
			E)	None of these.
27		The role of a tumor suppressor gene:
			A)	Is to encode a protein that stimulates cell division.
			B)	Is to prevent mistakes in DNA replication.
			C)	Is to allow cell division only under appropriate conditions.
			D)	All of these.
			E)	None of these.
28		Which of these are likely as a result of the two hit model?
			A)	Predisposition to cancer is inherited as a dominant trait.
			B)	Tumor formation is inherited as a dominant trait.
			C)	Individuals who have inherited a mutant copy of a tumor suppressor are more likely to develop tumors, but they usually occur at later ages of onset.
			D)	All of these.
			E)	None of these.
29		What is the normal interaction between the Rb protein and the E2F transcription factor?
			A)	Rb inhibits E2F activity, effectively preventing cell division.
			B)	Rb enhances E2F activity, effectively preventing cell division.
			C)	Rb inhibits E2F activity, increasing the rate of cell division.
			D)	Rb enhances E2F activity, increasing the rate of cell division.
30		p53 will stimulate a badly damaged cell to undergo apoptosis rather than proceeding through the cell cycle.
			A)	True
			B)	False
31		Which of the following is a common type of tumor suppressor genes?
			A)	Genes that increase the rate of the cell cycle or stimulate cell division.
			B)	Genes involved in performing DNA synthesis.
			C)	Genes involved in maintenance of cell cycle checkpoints.
			D)	All of these.
			E)	None of these.
32		The difference between benign tumors and malignant cancer is the type of mutation.
			A)	True
			B)	False
33		Why are cancer cells likely to accumulate mutations, including changes in chromosome number, over time?
			A)	They are less likely to attach chromosomes correctly to the mitotic spindle.
			B)	They are more likely to make mistakes in DNA synthesis.
			C)	They are allowed to divide despite potential errors in DNA synthesis or spindle assembly.
			D)	All of these.
			E)	None of these.