Student Center | Instructor Center | information Center | Home

Life, 4/e

Ricki Lewis, University of New York at Albany
Mariëlle Hoefnagels, University of Oklahoma
Douglas Gaffin, University of Oklahoma
Bruce Parker, Utah Valley State College

How Inherited Traits are Transmitted

Chapter Quiz


1	How was the work of Mendel unique compared with that of others studying plant genetics at the time?
		A)	Unlike the others, Mendel applied statistics to his results.
		B)	Mendel crossed hybrids only.
		C)	Mendel used artificial pollination.
		D)	All of these are correct.


2	In Mendel’s crosses with single traits in pea plants, the trait that masked the other was said to be _________________.
		A)	recessive
		B)	dominant
		C)	elementen
		D)	true-breeding


3	Mendel’s law of segregation states that
		A)	gametes segregate into traits during fertilization.
		B)	traits segregate into alleles during fertilization.
		C)	traits segregate when gametes form.
		D)	gametes segregate when traits form.


4	The basic unit of inheritance is a(n) ___________.
		A)	allele
		B)	trait
		C)	gene
		D)	chromosome


5	An individual with two identical alleles for a gene is called ______________.
		A)	homologous
		B)	homozygous
		C)	heterozygous
		D)	dominant


6	If an organism has been designated Tt, it is ________________.
		A)	homozygous dominant
		B)	heterozygous
		C)	homozygous recessive
		D)	homologous


7	Mendel’s pea plants had either yellow or green unripe pods. These characteristics represent an organism’s ______________.
		A)	adaptedness
		B)	genotype
		C)	phenotype
		D)	chromosomes


8	Organisms that vary from the wild-type are called _____________.
		A)	mutant
		B)	recessive
		C)	independent
		D)	dominant


9	The typical phenotypic ratio expected from a monohybrid cross involving simple dominance is __________.
		A)	1:1
		B)	4:0
		C)	3:1
		D)	2:2


10	When the genotype of an individual is unknown, what kind of cross should be made?
		A)	monohybrid cross
		B)	dihybrid cross
		C)	testcross
		D)	reciprocal cross


11	In a typical pedigree chart, a half-filled circle indicates a _____________.
		A)	recessive parent
		B)	non-affected male
		C)	affected female
		D)	carrier female


12	An organism has an unknown genotype and a geneticist is trying to determine whether it is homozygous dominant (red-skinned) or heterozygous. If the result of a testcross yielded a population of all red-skinned organisms, the organism must have been
		A)	homozygous dominant.
		B)	heterozygous.
		C)	homozygous recessive
		D)	The results are inconclusive using the information provided.


13	Which human disorder is inherited as an autosomal dominant?
		A)	phenylketonuria
		B)	Huntington disease
		C)	cystic fibrosis
		D)	sickle cell disease


14	True or False. The law of independent assortment states that inheritance of one trait does not depend on the transmission of a gene for another trait.
		A)	True
		B)	False


15	Using the product rule, what is the likelihood of obtaining a RRYY plant from dihybrid (RrYy) parents?
		A)	1/4
		B)	1/12
		C)	1/16
		D)	1/64


16	Lethal alleles are usually
		A)	homozygous dominant alleles.
		B)	heterozygous alleles.
		C)	homozygous recessive alleles.
		D)	carried on the Y chromosome.


17	True or False. Environmental conditions influence gene expression.
		A)	True
		B)	False


18	If 60 out of 100 cats that inherit the dominant allele for polydactyly actually have extra digits, the allele is said to be ______________.
		A)	expressed
		B)	completely penetrant
		C)	codominant
		D)	60% penetrant


19	Marfan syndrome and porphyria were historically difficult to trace through families or determine their mode of inheritance because of the variety of symptoms of each disease. Disorders or traits with many symptoms are ___________.
		A)	pleiotropic
		B)	epistatic
		C)	incompletely dominant
		D)	codominant


20	ABO blood type is an example of which type of dominance?
		A)	codominance
		B)	incomplete dominance
		C)	simple dominant/recessive traits
		D)	None of these is correct.


21	A cross of a red-flowered snapdragon plant with a white-flowered snapdragon produces a plant with pink flowers. This is an example of _____________.
		A)	pleiotropy
		B)	epistasis
		C)	incomplete dominance
		D)	codominance


22	A _____________ appears to be an inherited trait but is instead caused by an environmental factor.
		A)	multifactorial trait
		B)	phenocopy
		C)	variably expressive trait
		D)	epistatic gene


23	A complex trait determined by one or more genes plus the environment is ______________.
		A)	polygenic
		B)	multifactorial
		C)	quantitative
		D)	genetic heterogeneity


24	Identical twins result when a single fertilized egg divides in two. Another term for identical twin is ____________.
		A)	fraternal
		B)	maternal
		C)	monozygotic
		D)	dizygotic

2002 McGraw-Hill Higher Education
Any use is subject to the Terms of Use and Privacy Policy.
McGraw-Hill Higher Education is one of the many fine businesses of The McGraw-Hill Companies.