Chapter 14

A Punnett square A) is useful in predicting the result of genetic crosses between organisms of unknown genotypes. B) computes the probable genotype of future offspring C) identifies the gene locus where allelic variations are possible. D) tests for the presence of the allele responsible for Huntington's disease E) directly examines a fetus for genetic abnormalities.

A) is useful in predicting the result of genetic crosses between organisms of unknown genotypes.

The F1 offspring of Mendel's classic pea cross always looked like one of the two parental varieties because A) one allele was completely dominant over another B) each allele affected phenotypic expression. C) the traits blended together during fertilization. D) no genes interacted to produce the parental phenotype. E) different genes interacted to produce the parental phenotype.

A) one allele was completely dominant over another

Mendel conducted his most memorable experiments on A) peas B) roses C) guinea pigs. D) fruit flies. E) clones

A) peas

In cattle, roan coat white hairs) occurs in the color (mixed red and (Rr) offspring heterozygous homozygotes. of red (RR) and When two roan white r) cattle are crossed, the phenotypes of the progeny are found to be in the ratio of 1 red:2 roan:1 white Which of the following crosses could produce the highest percentage of roan cattle? A) red x white B) roan x roan C) white x roan D) red x roan E) All of the above crosses would give the same percentage of roan.

A) red x white

In a dihybrid cross, the expected proportion of offspring showing both recessive traits is A)1/16. B)3/16. C)9/16. D) 1/4 E) 1/32.

A)1/16.

Which blood type of a child would exclude the accused from paternity? A)AB, Rh negative B) B, Rh negative C)O, Rh negative D ) B , Rh positive E) None of these choices will exclude.

A)AB, Rh negative

A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt Which of the following genotypes is possible in a gamete from this organism? A)HT B) Hh C)HhTt D)T E)tt

A)HT

are of the planted Hydrangea plants of the same genotype in a large flower garden and s plants produce blue flowers others pink flowers. This can be best explained by A)environmental factors such as soil pH B) the allele for blue violet being completely dominant C) the alleles being codominant. D) the fact that a mutation has occurred. E) acknowledging that multiple alleles are involved

A)environmental factors such as soil pH

What is the expected phenotypic ratio of a cross between two orange-eyed MendAliens? A)3 black-eyed:1 orange-eyed B ) O black - eyed : 1 orange - eyed C) 1 black-eyed:3 orange-eyed D) 1 black-eyed:0 orange-eyed E) 1 black-eyed:1 orange-eyed

B ) O black - eyed : 1 orange - eyed

If their first two chüldren have normal probability that pigmentation, what is the their third child will be an albino? A)0 B) 1/4 C)1/2 D)3/4 E)1

B) 1/4

What is the probability that The couple decides to have a second child will be albino? A)0 B) 1/4 C)1/2 D)3/4 E) 1

B) 1/4

flowers and the are crossed. One parent Two true-breeding Assume independent assortment.) expect to have red, terminal flowers? the cross, how many of them flowers. If 1,000 F2 offspring flowers; all Fi individuals had red, axial other had white, terminal had red, axial stocks of garden peas resulted from would you A)65 B) 190 C) 250 D)565 E)750

B) 190

A couple who are both carriers of the gene for cystic fibrosis have two children who have cystic fibrosis. What is the probality that their next child will have cystic fribrosis

B) 25%

How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE? A)4 B) 8 C) 16 D) 32 E) 1/64

B) 8

In a cross between parents who both light-colored hair. What are the hair dark-haired traits, one child has straight exhibit the dominant curly- and genotypes of the parents? A)CCdd x ccDd B) CcDd x CcDd C) CcDd x ccdd D) Ccdd x CcDdE) CCDD x CcDd

B) CcDd x CcDd

The child's blood type is A, Rh negative. What can you say about the chances of a male with A, Rh positive blood being the father? A) He is the father. B) He might be the father C) He is not the father. D) He is almost certainly the father E) There is not enough information to make a decision.

B) He might be the father

What was the most significant result Gregor Mendel drew from his experiments with pea plants? A)There is considerable genetic variation in garden peas. B) Traits are inherited in discrete units, and are not the results of "blending." C) Re cessive genes occur more frequently in the F1 than do dominant ones. D) Genes are composed of DNA E) An organism that is homozygous for many recessive traits is at a disadvantage.

B) Traits are inherited in discrete units, and are not the results of "blending."

What is the genotype of individual D-3? A) WW only B) Ww only C)ww only D) WW or ww E) ww or Ww

B) Ww only

A 9:3:3:1 phenotypic ratio is characteristic of A) a monohybrid cross, B) a dihybrid cross C)a trihybrid cross. D) linked genes E) C and D

B) a dihybrid cross

What is a genetic cross called between an individual of unknown genotype and a homozygous recessive? A) a self-cross B) a testcros C) a hybrid cross D)an F1 cross E) a dihybrid cross

B) a testcross

For this trait, what is the genotype of the albino child? A) homozygous dominant B) homozygous recessive C) heterozygous D) hemizygous E) unknown, because not enough information is provided

B) homozygous recessive

Mendel's law of segregation was nearly impossible for most biologists to understand until there was a general understanding of A) dominance. B) meiosis. C) mitosis. D) pleiotropy E) epistasis.

B) meiosis.

Mendel's law of was nearly understanding of to understand until there was a general impossible for most biologists independent assortment A) Dominenc B) meiosis. C) mitosis. D) pleiotropy E) epistasis.

B) meiosis.

P- purple, pp- wlute. The offspring of a cross of two heterozygous purple-flowering plants (Ppx Pp) results in A) all purple-flowered plants. B) purple-flowered plants and white-flowered plants C) two types of white-flowered plants: PP and Pp D) all white-flowered plants. E) all pink-flowered plants.

B) purple-flowered plants and white-flowered plants

Which of the related to the others? following terms is least A)homozygous B) tetrad C) recessive D) heterozygous E) dominant

B) tetrad

What is the probability that their first child will be an albino? A)0 B)1/4 C)1/2 D)3/4 E ) I

B)1/4

Three babies were recently mixed up in a hospital. After consideration of the data below, which of the following represent the correct baby/parent combinations? A)I-3, II-1, III-2 B)I-1, 11-3, 111-2 C ) 1-2 , Π - 3 , 111-1 D)I-2, II-1, I11-3 E) I-3, II-2, I1-1

C ) 1-2 , Π - 3 , 111-1

In crossing a homozygous recessive with a heterozygote, what is the chance of getting an offspring with the homozygous recessive phenotype? A ) 0 % B ) 25 % C ) 50 % D ) 75 % E ) 100 %

C ) 50 %

assume simple dominance and Given the parents AABBCc x AabbCc. of the progeny will be expected to independent assortment. What proportion phenotypically resemble the first parent? A ) 1 / 4 B ) 1 / 8 C) 3/4 D)3/8 E) 1

C) 3/4

Which of the following is a possible phenotype for the father? A) A negative B) O negative C) B positive D) A positive E) O positive

C) B positive

The child's blood type is A. Rh negative What can you say about the man's chances of being the father? A) He is the father. B) He might be the father. C) He is not the father. D) He might not be the father E) There is not enough information to make a decision.

C) He is not the father.

A cross between homozygous purple-flowered and homozygous white-flowered pea plants results in offspring with purple flowers. This demonstrates A) the blending model of genetics. B) true-breeding. C) dominance D) a dihybrid cross. E) the mistakes made by Mendel.

C) dominance

A 9 purple to 7 white phenotype in sweet peas in the Fz generation is most likely due to A)linkage. B) trisomy 21. C) epistasis. D) crossing over E) pleiotropy

C) epistasis.

A plant with purple flowers is allowed to self-pollinate. Generation after generation, it produces purple flowers. This is arn example of A) hybridization. B) incomplete dominance. C) true-breeding. D) the law of segregation. E) polygenetics

C) true-breeding.

What is the genotype of individual B-57 A) WW only B) Ww only C) ww only D) WW or tww E) ww or Ww

C) ww only

Two blue budgies were crossed. Over the years, they produced 22 offspring, 5 of which were white. What are the most likely genotypes for the two blue budgies? A) yyBB and yyBB B) yyBB and yyBb C) yyBb and yyBb D) yyBB and yybb E) yyBb and yybb

C) yyBb and yyBb

Huntington's disease is caused by a dominant allele. If one of your parents has the disease, what is the probability that you, too, will have the disease? A) 1 B)3/4 C)1/2 D) 1/4 E) 0

C)1/2

What is the probability that their fourth child will have a homozygous genotype? A)0 B) 1/4 C)1/2 D)3/4 E) 1

C)1/2

A 1:2:1 phenotypic ratio in the F2 of A) complete dominance. B) multiple alleles. C)incomplete dominance. D) polygenic inheritance. E) pleiotropy

C)incomplete dominance.

Skin color in a fish is inherited via a single alleles. How many different genotypes gene with four different would be possible in this system? A)3 B) 6 C)8 D) 10 E) 16

D) 10

genotype for the son? Which of the following is a possible A)1BIB B) IBBRR C) IBiRr D) IBirr E ) İBİBRr

D) IBirr

Alleles A) are the result of hybridization. B) are present only in the Fi generation. C) occur in a 3:1 ratio. D) are alternative forms of a gene. E) don't affect the phenotypes until the F2 generation.

D) are alternative forms of a gene.

All the offspring of a cross between a black-eyed MendAlien and an orange-eyed MendAlien have black eyes. This means that the allele for black eyes is the allele for orange eyes. A) codominant to B) recessive to C) more aggressive than D) dominant to E) better than

D) dominant to

All the offspring of a cross between a red-flowered plant and a white-flowered plant have pink flowers. This means that the allele for red flowers is to the allele for white flowers. A) dominant B) codominant C) pleiotropic D) incompletely dominant E) recessive

D) incompletely dominant

Which of the following terms is least related to the others? A) segregation B) independent assortment C) homologous chromosomes D) pleiotropy E) random recombination

D) pleiotropy

The fact that all principle of independent assortmert traits studied by Mendel obeyed the seven of the garden pea means that the traits are on the same pair of C) seven pairs of alleles determining these B) diploid number of garden peas is 7 A)haploid number of garden peas is 7 homologous chromos D) seven pairs of alleles traits behave as if they are on different determining these chromosomes E) formation of gametes in plants is by mitosis only

D) seven pairs of alleles traits behave as if they are on different determining these chromosomes

Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. This indicates A) that the parents were true-breeding for contrasting traits. B) incomplete dominance. C) that a blending of traits has occurred. D) that the parents were both heterozygous. E) that each offspring has the same alleles.

D) that the parents were both heterozygous.

The probability that four coins will come up heads when flipped simultaneously is A)1/4 (0.25) B) 1/2 C)1/8 (0.125), D)1/16 (0.063). E) 1/64 (0016),

D)1/16 (0.063)

Black fur in mice (B) is dominant to brown fur (b). Short tails (T) is dominant to long tails (t). What fraction of the progeny of the cross BbTt x BBtt will have black fur and long tails? A ) 1 / 16 B) 3/16 C)3/8 D)1/2 E) 9/16

D)1/2

whom children, hair. Both all of eyes and blond for brown the other eyes is have brown A couple has three parents (Rr). one is a What is the are homozygous blond (or) and probability brown-eyed (BB), but a redhead that their next child will be a redhead? A)1/16 B) 1/8 C)1/4 D)1/2 E) 1

D)1/2

The mother is now pregnant for a third time, and her doctor tells her she is carrying fraternal twins. What is the probability that both children will have normal pigmentation? A)3/4 B) 1/4 C)1/16 D)9/16 E) 16/16

D)9/16

Which of the following is a possible genotype for the mother? A ) IAIA RR B) IAIARr C) IAirr D)IAiRr E)IAIRR

D)IAiRr

Tallness (T) is dominant to dwarfness (). while red (R) flower color is dominant to white (). The heterozygous condition results in pink (Rr) flower color. A dwarf, is crossed homozygous red snapdragon with a plant homozygous for tallness and white flowers. What are the genotype and phenotype of the Fi individuals? A)ttRr dwarf and pink B) ttrr dwarf and white C) TtRr-tall and red D)TtRr-tall and pink E) TTRR-tall and red

D)TtRr-tall and pink

In snapdragons, heterozygotes have pink flowers, whereas the two homozygotes have red flowers or white flowers. When plants with red flowers are crossed with plants with white flowers, what proportion of the offspring will have pink flowers? A ) 0 % B ) 25 % C ) 50 % D ) 75 % E ) 100 %

E ) 100 %

What is the probability that individual C-1 is Ww? A)3/4 B)1/4 C)2/4 D)2/3 E) 1

E) 1

In a cross probability of producing the genotype AaBlCcx AaBlCc, what is the AABBCC A)1/4 B)1/8 C)1/16 D) 1/32 E) 1/64

E) 1/64

What is the expected phenotypic ratio of the following cross: AaBb x AaBb? In this example A is dominant to a and Bis dominant to b A)16:00:0 B) 8:4:2:2 C)4:4:4:4 D) 1:1:1 E) 9:3:3:1

E) 9:3:3:1

A green budgie is crossed with a blue budgie. Which of the following results is not possible? A)all green offspring B) all blue offspring C)all white offspring D)all yellow offspring E) All of the above are possible, but with different probabilities

E) All of the above are possible, but with different probabilities

People with sickle-cell trait A) are heterozygous for the sickle-cell allele. B) are usually healthy. C) have increased resistance to malaria D) produce normal and abnormal hemoglobin. E) All of the above are true.

E) All of the above are true.

Which of the following is a correct historical progression of these three events, from first to last? A) I,II,III B) II,III,I C) I,III, II D) III, II, I E) III, I, II

E) III, I, II

Roan color in cattle is the result of incomplete dominance between red and white color genes (Rr). How would one produce a herd of pure-breeding roan-colored cattle? A) cross roan with roan B) cross red with white C) cross roan with red D) cross roan with white E) It cannot be done

E) It cannot be done

The inheritance of color in budgies is an example of what genetic phenomenon? A) pleiotropy B) penetrance C) polygenic inheritance D) dominance E) epistasis

E) epistasis

Which of the following terms is least related to the others? A) pedigree B) karyotype C) amniocentesis D) chorionic villus sampling E) epistasis

E) epistasis

Which of the following is an example of polygenic inheritance? A) pink flowers in snapdragons B) the ABO blood groups in humans C) sex linkage in humans D) white and purple color in sweet peas E)skin pigmentation in humans

E)skin pigmentation in humans

This is caused by a dominant single gene defect and generally does not appear until the individual is 30-40 years of age

Huntingtons disease

The phenotype of the heterozygote differs from the phenotypes of both homozygotes.

Incomplete dominance

In certain plants, tall is dominant to short. If a heterozygous plant is crossed with a homozygous tall plant, what is the probability that the offspring will be short? A) 1/2 B) 1/4 C)0 D) 1 E) 1/6

O

her next child will be a daughter is A woman has six sons. The chance that A) 1 B) 0 C) 1/2 D)1/6 E) 5/6

OC) 1/2

Effects of this recessive single gene can be completely overcome by regulating the diet of the affected individual.

Phenylketonuria

Individuals with this disorder are unable to metabolize gangliosides, which affects proper brain development. Affected individuals die in early infancy

Tay-sachs disease

This results from having defective membrane proteins that normally function in chloride ion transplant.

cystic fibrosis

A couple who are both carriers of the gene for cystic fibrosis have two children who have cystic fibrosis. What is the probability that their next child will have cystic fibrosis? A ) 0 % B ) 25 % C ) 50 % D ) 75 % E ) 100 %

d )75 %

One example is the ABO blood group system.

multiple alleles

the ability of a single gene to have multiple phenotype effects

pleiotrophy

Substitution of the "wrong amino acid in the hemoglobin protein results in this disorder

sickel cell disease