Multiple Choice

Please answer all questions

1		Alternate forms of a gene having the same position on a pair of chromosomes and affecting the same trait are called______. (p. 404)
			A)	chromatids
			B)	alleles
			C)	DNA segments
			D)	centrioles
2		Tay-Sachs disease is due to a lack of the enzyme _______. (p. 407)
			A)	lypase
			B)	dehydrogenase
			C)	Hex A
			D)	amylase
3		_____ is the most common lethal genetic disease among Caucasians in the U.S. (p. 407)
			A)	Tay-Sachs disease
			B)	Huntington disease
			C)	Cystic fibrosis
4		The problem in cystic fibrosis is that ________ fail to pass through plasma membrane channel proteins, so ducts lack the correct amount of water. (p. 407)
			A)	potassium ions
			B)	sodium ions
			C)	chloride ions
			D)	digestive enzymes
5		Huntington disease ________ . (p. 407)
			A)	causes tumors
			B)	affects the brain
			C)	affects the liver
6		Neurofibromatosis and Huntington disease are inherited as __________ traits. (p. 408)
			A)	autosomal recessive
			B)	autosomal dominant
			C)	X-linked recessive
			D)	The mode of inheritance of these diseases is unknown.
7		Regarding Huntington disease, which of the following is true? (p. 408)
			A)	The gene is located on chromosome 4.
			B)	Persons most at risk have inherited the disease from their fathers.
			C)	The pattern of inheritance for this disease may follow genomic imprinting.
			D)	All of these are correct.
8		People appear normal but can pass on an allele for a genetic disorder are called ______. (p. 409)
			A)	deficient
			B)	recessive
			C)	latent
			D)	carriers
9		Give an example of a genetic disorder that is controlled by polygenes and therefore subject to environmental influence. (p. 411)
			A)	schizophrenia
			B)	hypertension
			C)	cancer
			D)	All of these are correct.
10		ABO alleles determine the presence or absence of ________ on the red blood cells. (p. 412)
			A)	antigens
			B)	antibodies
			C)	fragments
			D)	ions
11		The following blood types are possible if parents have genotypes AO and BO. (p. 412)
			A)	A
			B)	B
			C)	O
			D)	All of these are correct.
12		Two individuals with the sickle-cell trait can produce individuals with ________ phenotypes. (p. 413)
			A)	one
			B)	two
			C)	three
			D)	four
13		X-linked recessive disorders include _______. (pp. 415, 416)
			A)	color blindness
			B)	hemophilia
			C)	muscular dystrophy
			D)	All of these are correct.
14		The type of hemophilia caused by the absence of clotting factor VIII is _______. (p. 415)
			A)	hemophilia A
			B)	hemophila B
15		_______ traits are controlled by genes believed to be turned on and off by hormones. (p. 418)
			A)	Sex-linked
			B)	Codominant
			C)	Sex-influenced
			D)	Dominant