Choose the best answer

1			In order to ensure he had pure-breeding plants for his experiments, Mendel Need a Hint?
			A)	cross-fertilized each variety with each other.
			B)	let each variety self-fertilize for several generations.
			C)	removed the female parts of the plants.
			D)	removed the male parts of the plants.
2			When two parents are crossed, the offspring are referred to as the Need a Hint?
			A)	recessives.
			B)	testcross.
			C)	F1 generation.
			D)	F2 generation.
3			A cross between two individuals results in a ratio of 9:3:3:1 for four possible phenotypes. This is an example of a Need a Hint?
			A)	dihybrid cross.
			B)	monohybrid cross.
			C)	testcross.
			D)	none of these.
4			Human height shows a continuous variation from the very short to the very tall. Height is most likely controlled by Need a Hint?
			A)	epistatic genes.
			B)	environmental factors.
			C)	sex-linked genes.
			D)	multiple genes.
5			In the human ABO blood grouping, the four basic blood types are type A, type B, type AB, and type O. The blood proteins A and B are Need a Hint?
			A)	simple dominant and recessive traits.
			B)	incomplete dominant traits.
			C)	codominant traits.
			D)	sex-linked traits.
6			Which of the following describes symptoms of sickle cell anemia? Need a Hint?
			A)	poor blood circulation due to abnormal hemoglobin molecules
			B)	sterility in females
			C)	failure of blood to clot
			D)	failure of chloride ion transport mechanism
7			What finding finally determined that genes were carried on chromosomes? Need a Hint?
			A)	heat sensitivity of certain enzymes that determined coat color
			B)	sex-linked eye color in fruit flies
			C)	the finding of complete dominance
			D)	establishing pedigrees
8			A genetic map can be used to determine Need a Hint?
			A)	the relative position of alleles on chromosomes.
			B)	restriction sites on chromosomes.
			C)	the frequency of recombination between two genes.
			D)	all of these.
9			A Barr body is a(n) Need a Hint?
			A)	result of primary nondisjunction.
			B)	inactivated Y chromosome.
			C)	gene that plays a key role in male development.
			D)	inactivated X chromosome.
10			Down syndrome in humans is due to Need a Hint?
			A)	three copies of chromosome 21.
			B)	monosomy.
			C)	two Y chromosomes.
			D)	three X chromosomes.