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______.
			A)	chromatids
			B)	alleles
			C)	DNA segments
			D)	centrioles
2		Tay-Sachs disease is due to a lack of the enzyme _______.
			A)	lypase
			B)	dehydrogenase
			C)	Hex A
			D)	amylase
3		_____ is the most common lethal genetic disease among Caucasians in the U.S.
			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.
			A)	potassium ions
			B)	sodium ions
			C)	chloride ions
			D)	digestive enzymes
5		Huntington disease ________ .
			A)	causes tumors
			B)	affects the brain
			C)	affects the liver
6		Neurofibromatosis and Huntington disease are inherited as __________ traits.
			A)	autosomal recessive
			B)	autosomal dominant
			C)	X-linked recessive
			D)	The mode of inheritance of these diseases is unknown.
7		People appear normal but can pass on an allele for a genetic disorder are called ______.
			A)	deficient
			B)	recessive
			C)	latent
			D)	carriers
8		Give an example of a genetic disorder that is controlled by polygenes and therefore subject to environmental influence.
			A)	schizophrenia
			B)	hypertension
			C)	cancer
			D)	All of these are correct.
9		ABO alleles determine the presence or absence of ________ on the red blood cells.
			A)	antigens
			B)	antibodies
			C)	fragments
			D)	ions
10		The following blood types are possible if parents have genotypes AO and BO.
			A)	A
			B)	B
			C)	O
			D)	All of these are correct.
11		Two individuals with the sickle-cell trait can produce individuals with ________ phenotypes.
			A)	one
			B)	two
			C)	three
			D)	four
12		X-linked recessive disorders include _______.
			A)	color blindness
			B)	hemophilia
			C)	muscular dystrophy
			D)	All of these are correct.
13		The type of hemophilia caused by the absence of clotting factor VIII is _______.
			A)	hemophilia A
			B)	hemophila B
14		_______ traits are controlled by genes believed to be turned on and off by hormones.
			A)	Sex-linked
			B)	Codominant
			C)	Sex-influenced
			D)	Dominant