Deck 14: Patterns of Inheritance

Question 1

In dogs,there is a hereditary deafness caused by a recessive allele,d.A kennel owner has a male dog that she wants to use for breeding purposes if possible.The dog can hear,but the owner is unsure of the genotype.She does a testcross (crosses it to a homozygous recessive dog),and two of the five offspring are deaf.This means that the male dog

A)has the genotype Dd
B)has the genotype DD
C)has the genotype dd
D)is actually deaf
E)is still of unknown genotype since there were offspring of both deaf and hearing phenotypes

Answer 1

A

Question 2

Eyelash length is an inherited trait.In the human population,there is an eyelash length gene.There are two possible variants of this gene - an allele for long eyelashes (> 1cm)and an allele for short eyelashes (1 cm or less).The allele for long eyelashes is dominant (L)and the allele for short eyelashes is recessive (l).An individual who is heterozygous for eyelash length would have which of the following phenotypes?

A)ll
B)LL
C)Ll
D)Long eyelashes
E)Short eyelashes

Answer 2

D

Question 3

The single-factor crosses performed by Mendel support the observation that

A)the two alleles for a given gene are distributed randomly among an individual's gametes.
B)the two alleles for a given gene are found within the same gamete.
C)if the recessive alleles for two different genes are on the same chromosome,they will never be found within the same gamete.
D)only the dominant alleles for a given trait are found in an organism's gametes.
E)if the dominant alleles for two different genes are on different chromosomes,they will never be found within the same gametE.

Answer 3

A

Question 4

Type 1 fucosidosis is a rare human disease.Patients cannot hydrolyze the disaccharide fucose,and as a result have severe neurological decline and die by age 6.The disease is due to a defect in the gene that encodes the lysosomal enzyme that breaks down fucose ( $\alpha$ -1-fucosidase),and is inherited in an autosomal recessive manner.Jane and John have a child who has Type 1 fucosidosis.What is the probability that their next child will also have the disease?

A)No chance
B)1/4
C)1/2
D)3/4
E)4/4 or 100%

Question 5

Eyelash length is an inherited trait.In the human population,there is an eyelash length gene.There are two possible variants of this gene - an allele for long eyelashes (> 1cm)and an allele for short eyelashes (1 cm or less).The allele for long eyelashes is dominant (L)and the allele for short eyelashes is recessive (l).An individual who is heterozygous for eyelash length would produce which of the following gametes?

A)All gametes would have the l allele.
B)All gametes would have the L allele.
C)Half of the gametes would have the L allele and half of the gametes would have the l allele.
D)The proportion of gametes receiving each allele would be random;the process of meiosis is very disorganized and chromosomes are not separated in an ordered fashion.
E)None of the gametes would have the eyelash gene;gametes do not have eyelashes.

Question 6

What is a dominant allele?

A)An allele that is very prevalent in a population
B)An allele that will only have an affect on phenotype in a haploid organism;otherwise its presence will be masked
C)An allele that has no noticeable affect on an organism's phenotype
D)In a heterozygous individual,the allele that determine's the phenotype
E)An allele whose effect is masked unless in the homozygous condition

Question 7

The two-factor crosses performed by Mendel support the observation that

A)alleles of one gene are distributed randomly among an individual's gametes,independent of the alleles for other genes.
B)traits that are encoded by genes on different chromosomes are never found within the same gamete.
C)the F₁ generation can display phenotypes in combinations different from those seen in the P generation.
D)the F₂ generation will only display phenotypes in the same combinations as the P generation.
E)self-fertilization of the F₁ generation will produce 100% heterozygous plants at both loci.

Question 8

Anury is the absence or abbreviation of the tail in sheep (and also other animals).It is inherited in an autosomal dominant fashion.A ram with anury is mated to a ewe with a normal tail.The ram's father had anury,his mother did not.What is the probability that the ram and ewe will produce a lamb with anury? (ram = male;ewe = female)

A)25%
B)50%
C)75%
D)100%
E)No chance

Question 9

Polydactyly is a dominant trait that results in extra fingers and toes in humans.A man with polydactyly marries a woman with 10 fingers and toes.They have a child that has a normal number of digits.The phenotype of the man's father is unknown,but his mother has a normal phenotype.What are the genotypes of the married couple? (D = polydactyl allele;d = wild type allele)

A)woman Dd,man dd
B)woman DD,man dd
C)woman dd,man DD
D)woman dd,man Dd
E)woman DD,man Dd or dd

Question 10

The probability of obtaining a dominant phenotype from self-fertilization of a heterozygous individual is

A)25%
B)50%
C)75%
D)100%

Question 11

A cross between two pea plants results in 732 purple and 268 white plants.What is (are)the genotype(s)and phenotype(s)of the parents that produced these offspring?

A)both parents are heterozygous purple
B)one parent is homozygous purple,second parent is homozygous white
C)one parent is heterozygous purple,second parent is heterozygous white
D)one parent heterozygous purple,second parent homozygous white
E)one parent is homozygous purple,second parent is heterozygous white

Question 12

How can you determine the genotype of a plant showing the dominant phenotype of red color?

A)The phenotype reflects the genotype,so the plant must be homozygous for the trait.
B)Cross the red plant with a white plant to see if any white plants appear.
C)Cross the red plant with other red plants to see if any white plants appear.
D)Cross the red plant with a white plant to see if any red plants appear.
E)Cross the red plant with another red plant,and then cross the F₁ population with each other to see if any white plants appear.

Question 13

Eyelash length is an inherited trait.In the human population,there is an eyelash length gene.There are two possible variants of this gene - an allele for long eyelashes (> 1cm)and an allele for short eyelashes (1 cm or less).How many eyelash length alleles does an individual have in one of her/his somatic cells?

A)46
B)23
C)2
D)3
E)1

Question 14

In goats,the gene for coat color is on an autosome and light brown color is dominant to black.A light brown male is mated to a black female,producing a black kid (baby goat).If they produce another kid,could it be light brown? If so,what are the chances of it being light brown?

A)No,since the black allele is present all offspring will be black
B)Yes,100% since the first kid was black the next one has to be light brown
C)Yes,75% since light brown is dominant
D)Yes,50% as the male must be heterozygous for color
E)Yes,but it will depend on whether the kid is male or female

Question 15

Tay Sachs is a lysosomal storage disease that is inherited in an autosomal recessive manner.Individuals with Tay Sach have a defect in the gene encoding hexosaminidase A,a lysosomal enzyme that breaks down cell membrane components called gangliosides.The inability to break down gangiosides causes harmful quantities of this lipid to accumulate in nerve cells of the brain,eventually leading to premature death of affected cells.There is no known cure for the disease,and death usually occurs by age 4.(T= dominant allele;t = recessive allele)Jack and Jill have a child who has Tay-Sachs.What do you know about the genotypes of Jack and Jill?

A)Both are heterozygous
B)One is TT and the other is tt
C)Both are TT
D)Both are tt
E)It's impossible to tell.Since both are adults,they do not have the diseasE.But,they could either be TT or Tt

Question 16

In humans,having dimples in the cheeks is a dominant trait.If a child has dimples but only one of her parents does,what are the genotypes of her parents? (D = dimples;d = no dimples)

A)One parent dd,other parent DD
B)One parent dd,other parent Dd
C)One parent Dd,other parent DD
D)One parent must be DD,the other parent could be either dd or Dd
E)One parent must be dd,the other parent could be either Dd or DD

Question 17

Type 1 fucosidosis is a rare human disease.Patients cannot hydrolyze the disaccharide fucose,and as a result have severe neurological decline and die by age 6.The disease is due to a defect in the gene that encodes the lysosomal enzyme that breaks down fucose ( $\alpha$ -1-fucosidase),and is inherited in an autosomal recessive manner.Which of the following statements is ACCURATE about Type1 fucosidosis?

A)Ff and ff individuals will have the disease
B)Ff individuals will have the disease,because anyone with the mutant allele will have the disease
C)Ff individuals make enough $\alpha$ -1-fucosidase to break down fucose and do not exhibit the condition
D)Two carriers for Type I fucosidosis have no chance of having a normal child
E)Both Ff individuals will have the disease,because anyone with the mutant allele will have the disease AND two carriers for Type I fucosidosis have no chance of having a normal child

Question 18

In humans,freckles are inherited via a simple Mendelian pattern.A male is heterozygous for freckles,and he has freckles.If he marries a woman who is also heterozygous for freckles,______ percent of their children will be freckled and __________ percent of their children will be heterozygous.

A)100%,100%
B)75%,50%
C)75%,25%
D)50%,50%
E)100%,75%

Question 19

What is a testcross?

A)Any genetics cross you do in order to test a hypothesis.
B)Any genetics cross you see on an exam
C)A cross between two organisms of different species
D)A cross between an organism of unknown genotype with a homozygous recessive individual
E)A cross between two true-breeding individual (such as we see in the P generation)

Question 20

Eyelash length is an inherited trait.In the human population,there is an eyelash length gene.There are two possible variants of this gene - an allele for long eyelashes (> 1cm)and an allele for short eyelashes (1 cm or less).The allele for long eyelashes is dominant (L)and the allele for short eyelashes is recessive (l).An individual who is heterozygous for eyelash length would have which of the following genotypes?

A)ll
B)Ll
C)LL
D)Short eyelashes
E)Long eyelashes

Question 21

Roberts Syndrome is an extremely rare genetic disorder that is characterized by mild to severe prenatal retardation or disruption of cell division,leading to malformation of the bones in the skull,face,arms,and legs.Shown below is a pedigree for a family with Robert's Syndrome.Based on this pedigree what mode of inheritance does Roberts Syndrome exhibit?

A)autosomal dominant
B)autosomal recessive
C)sex-linked dominant
D)sex-linked recessive
E)random

Question 22

Huntington disease is a neurodegenerative genetic disorder that typically manifests itself around age 40.A 25-year-old woman comes to your genetic counseling center because she knows that Huntington disease occurs in members of her father's family.Her paternal grandfather was afflicted,but so far her 50-year-old father shows no symptoms.Her two great-great grandmothers on her father's side were healthy well into their 90s,but one of her great-great grandfathers died of unknown causes at 45.Testing for Huntington disease is extremely expensive,but she is concerned that she may fall victim to this disease and wants to plan her life accordingly.After examining her pedigree you advise her to

A)get tested because there is no possibility that she is homozygous.
B)not get tested because only males in her family get the disease.
C)get tested because her father could be a carrier.
D)not get tested because her father is only a carrier and it is very unlikely her mother is a carrier.
E)not get tested because her 50-year-old father shows no symptoms.

Question 23

What data would you expect to see regarding the distribution of phenotypes from a cross of purple pea plants that are heterozygous for flower color and plant height? (Purple is dominant to white;dwarf is dominant to tall. )

A)63 purple dwarf;25 purple tall;19 white dwarf;7 white tall
B)132 purple dwarf;138 white tall
C)54 purple dwarf;6 white tall
D)100% purple dwarf
E)27 purple dwarf;28 purple tall;31 white dwarf;29 white tall

Question 24

What features of meiosis allow for independent assortment of chromosomes?

A)Random alignment of homologous chromosomes on the metaphase plate
B)Separation of sister chromatids
C)Reduction of chromosome number from diploid to haploid
D)Both the separation of sister chromatids and the reduction of chromosome number from diploid to haploid

Question 25

In wolves,gray coat color (G)is dominant to black (g)and brown eyes (B)are dominant to blue (b).The genes that control these traits are located on different chromosomes.The alpha male of the pack has the dominant phenotype for both traits and is heterozygous for both traits.The alpha female has brown eyes and a black coat;she is heterozygous for eye color.The alpha male and the alpha female mate.What proportion of their offspring will have the same phenotype as the mother?

A)1/16
B)3/16
C)3/8
D)1/2
E)None

Question 26

Color blindness is a recessive X-linked trait.A normal couple has a color-blind child.Who else in this family is probably color blind?

A)the child's maternal grandfather
B)the child's maternal grandmother
C)the child's paternal grandfather
D)the child's paternal grandmother
E)the child's maternal grandmother or grandfather

Question 27

In Hodags (mythical creatures of Wisconsin),brown fur (B)is dominant over gray fur (b)and long horns (H)are dominant over short horns (h).Two true-breeding hodags,one with brown fur and long horns and the other with gray fur and short horns mate and produce an F₁.Two F₁ individuals are mated.What proportion of the offspring will exhibit a phenotypic combination that is different from the P generation? Assume the genes for fur color and horn length are on different chromosomes.

A)1/2
B)9/16
C)3/16
D)6/16
E)1/16

Question 28

In mammals,males are ________ and females are _______ for their sex chromosomes.

A)heterozygous,homozygous
B)hemizygous,homozygous
C)homozygous,heterozygous
D)hemizygous,heterozygous
E)heterozygous,hemizygous

Question 29

Hemophilia A is an X-linked recessive genetic condition.In humans it is due to a mutation in the F8 gene,which encodes a protein called coagulation factor VII.Coagulation factors are proteins important in blood clotting.Individuals with hemophilia,when injured,bleed longer than a normal,healthy individual;the inability to normally clot blood can be life threatening.Which of the following statements is NOT a reason why hemophilia is much more common in males than in females?

A)A female with one defective allele makes enough normal coagulation factor VII to clot blood and will not have hemophilia A
B)Males are hemizygous for the F8 gene,so they will have hemophilia A if they have one defective allele
C)Females have to receive a defective allele from both their mother and their father to get hemophilia A
D)Males have to receive a defective allele only from their father to get hemophilia A

Question 30

A homologous pair of chromosomes at the beginning of mitosis will possess _______ alleles for each locus.

A)2
B)4
C)8
D)1
E)50% of the

Question 31

An X-linked gene is

A)a gene that encodes traits seen only in females.
B)a gene on the X chromosome.
C)a gene found on any chromosome;they are X-shaped when they are metaphase chromosomes.
D)a gene that is turned on (makes protein)only when the female hormone estrogen is present.
E)a gene on the X chromosome that encodes traits seen only in females.

Question 32

Nearsightedness is dominant to normal vision and hazel eyes are dominant to blue eyes.A nearsighted woman with hazel eyes who is heterozygous for both traits marries a man with normal vision and hazel eyes.His genotype for eye color is the same as his wife's.Their three children all have blue eyes and normal vision.What is the probability that their next child will have blue eyes and be nearsighted?

A)1/4
B)1/2
C)3/8
D)1/8
E)5/8

Question 33

An organism has one Z chromosome and one W chromosome.That organism is

A)a female bird.
B)a male bird.
C)a female insect.
D)a male insect.
E)a male or female human.

Question 34

Roberts Syndrome is an extremely rare genetic disorder that is characterized by mild to severe prenatal retardation or disruption of cell division,leading to malformation of the bones in the skull,face,arms,and legs.Shown below is a pedigree for a family with Robert's Syndrome.What is the genotype of individual II-C? (R = wild type;r = Robert's syndrome)

A)RR
B)rr
C)Rr
D)R
E)r

Question 35

For mechanisms of sex determination,which of the following is incorrectly paired?

A)X-Y,cow
B)X-O,grasshopper
C)ZZ-ZW,bluebird
D)1n-2n,pea plant
E)high temperature-low temperature,alligator

Question 36

Incomplete dominance is when

A)the phenotypes of a heterozygote and a homozygous dominant are indistinguishable.
B)the phenotype of a heterozygote is not the same as either parent,but it is somewhere between the two parents.
C)the phenotype of a heterozygote clearly exhibits the phenotypes of both parents (it is not an intermediate).
D)an allele is dominant at some times and recessive at others.
E)the phenotypic expression at one locus alters the gene at a second locus.

Question 37

In wolves,gray coat color (G)is dominant to black (g)and brown eyes (B)are dominant to blue (b).The genes that control these traits are located on different chromosomes.The alpha male of the pack has the dominant phenotype for both traits and is heterozygous for both traits.The alpha female has brown eyes and a black coat;she is heterozygous for eye color.Which option represents gametes that would be made by the alpha female?

A)B,b,and g
B)Bg and bg
C)Bb and gg
D)BG,Bg,bG,bg
E)None of these

Question 38

An organism that is heterozygous for two traits can produce a maximum of _______ different gametes for these traits.

A)2
B)4
C)2;if they are on the same chromosome
D)27
E)8

Question 39

Human males produce

A)sperm,half contain an X chromosome,half contain a Y chromosome.
B)sperm with neither an X nor a Y;gametes do not contain sex chromosomes.
C)gametes,all contain a Y chromosome.
D)sperm,all contain an X chromosome.
E)gametes,all contain both an X chromosome and a Y chromosomE.

Question 40

Hemophilia is a sex-linked recessive condition that results in deficient blood clotting.The disease causes excessive bleeding which occurs spontaneously or upon slight injury.In dogs (as in humans)hemophilia is caused by a defect in a gene on the X chromosome.What will be the results of mating between a normal,non-carrier female dog and a male dog with hemophilia?

A)All female offspring will be normal and half the male offspring will have hemophiliA.
B)Half the male offspring will be normal and half will have hemophilia;all females will be carriers.
C)All the female offspring will be normal and all male offspring will be carriers.
D)Half the female offspring will have hemophilia and half will be carriers,all male offspring will be normal.
E)All of the offspring will be normal,but all females will be carriers.

Question 41

The law of independent assortment states that the two alleles of the same gene will segregate from each other during gamete formation.

Question 42

A man with pattern baldness and a woman who has no baldness have a son who develops pattern baldness.Their son has a daughter who also develops pattern baldness.They determine that her expression of this trait is not a symptom of a medical condition.If her mother does not have pattern baldness,the daughter's genotype is ________ and her mother's genotype is ________.

A)BB,bb
B)BB,Bb
C)bb,BB
D)Bb,Bb
E)bb,Bb

Question 43

An individual with an SRY gene is a male mammal.

Question 44

The sex of all animals is determined by chromosomes.

Question 45

Which of the following statements is not part of Morgan's Theory of Independent Assortment?

A)Alleles for different genes on the same chromosome are usually inherited together.
B)Crossing-over events during meiosis results in the exchange of genetic information between homologues.
C)The closer genes are to each other on the chromosome,the less likely a crossover will occur between them.
D)Linked genes are always inherited together.
E)All of these statements are part of Morgan's Theory of Independent Assortment.

Question 46

If you were to examine a typical population at a single locus,you would find more copies of the wild-type allele than any other allele.

Question 47

If a pink snapdragon is self-fertilized,the offspring are red,pink,or white.What type of inheritance pattern does flower color exhibit in this example?

A)X-linked.
B)incomplete dominance
C)dominance
D)incomplete recessive
E)recessive

Question 48

In rabbits,spotted coat (S)is dominant to solid color (s)and black (B)is dominant to brown (b).A true-breeding black spotted rabbit is mated to a true-breeding brown solid rabbit to produce a heterozygous F₁ generation.Two F₁ individuals are mated,and you do not see a 9:3:3:1 (black spotted: black solid: brown spotted: brown solid)ratio of offspring,but instead see that almost all offspring are a non-recombinant phenotype.This tells you that

A)that the genes for fur pattern (spotted vs.non-spotted)and fur color assort independently
B)that the genes for fur pattern (spotted vs.non-spotted)and fur color are on the same chromosome
C)that the genes for fur pattern (spotted vs.non-spotted)and fur color are on different chromosomes
D)that the genes for fur pattern (spotted vs.non-spotted)and fur color are on the X-chromosome and Y-chromosome,repectively.
E)that fur pattern (spotted vs.non-spotted)and fur color are maternally inherited

Question 49

_________ occurs when 50% of a protein produces a different phenotype than that produced by 100% or 0% of the protein.

A)Incomplete dominance
B)Recessive inheritance
C)Codominance
D)Loss of function mutation
E)Hybridization

Question 50

The inheritance pattern where two or more genes do not assort independently because they are close together on the same chromosome is called

A)Mendelian inheritance.
B)epistasis.
C)genomic imprinting.
D)linkage.
E)dominancE.

Question 51

When a single-gene mutation can have phenotypic effects at multiple stages of development,it is

A)pleiotropic.
B)incompletely dominant.
C)recessive.
D)causing a disease.
E)X-linked.

Question 52

A locus encodes different genes in different individuals of the same species.

Question 53

Imagine that horn color in Hodags (folkloric creatures of Wisconsin)is controlled by a single gene.You mate a Hodag homozygous for a bright orange horns (C^OC^O)with a Hodag homozygous for ivory horns (C^IC^I).Numerous offspring are produced,all with pale orange horns.This pattern of inheritance of horn color can best be described as

A)X-linked.
B)recombination.
C)incomplete dominance.
D)complete dominance.
E)environmental effects on phenotypE.

Question 54

What quality of the traits that Mendel chose to study allowed him to establish the basic laws of inheritance?

A)The genes for most of the traits were linked.
B)The genes for all of the traits had more than two alleles each.
C)The alleles that he studied were either dominant or recessive.
D)The alleles that he studied would blend and show an intermediate phenotype.
E)The traits he studied were never controlled by genes on the chloroplast.

Question 55

A mutation in a single gene always has only one discrete effect on an individual's phenotype.

Question 56

The color of petunia flower can be changed from red to blue by altering the pH of the soil.This is an example of

A)norm of pH.
B)the environment influencing the phenotype.
C)codominance.
D)incomplete dominance.
E)range of inheritancE.

Question 57

Offspring receive both the alleles for a given trait from one parent.

Question 58

Pea plants cannot self-fertilize because an individual plant is either female or male,having either ovaries or stamens but not both.

Question 59

In the sweet pea crossing experiment by Bateson and Punnet,the F₂ generation had many more offspring with the phenotypes of purple flowers with long pollen (PL)and red flowers with round pollen (pl)than expected from independent assortment.This is because

A)in these sweet peas,there are always more PL gametes than there are pl gametes.
B)in sweet peas,the alleles for flower color and pollen shape are on the same chromosome.
C)In sweet peas,the alleles for flower color and pollen shape are next to each other on the same chromosome.
D)In sweet peas,the allele for flower color is in the nuclear genome and the allele for pollen shape is on the chloroplast genome.
E)All of these are correct.

Question 60

Imagine that horn color in Hodags (folkloric creatures of Wisconsin)is controlled by a single gene.You cross an orange-horned Hodag with an ivory-horned Hodag and get an F₁.Numerous offspring are produced,all with pale orange horns.You then cross two F₁ individuals.What phenotypic ratio would you expect in the F₂ generation?

A)9 bright orange: 6 light orange: 1 ivory
B)1 bright orange: 2 light orange: 1 ivory
C)3 bright orange: 1 ivory
D)1OO: 2OI: 1II
E)3OO: 1 II

Question 61

Which of the following organelle(s)has/have a genome separate from the genome in the cell nucleus?

A)mitochondria
B)chloroplasts
C)nucleolus
D)both the mitochondria and chloroplasts
E)both the mitochondria and the nucleolus

Question 62

The genomes of mammalian mitochondria contain

A)a total of 37 genes.
B)genes for proteins used in oxidative phosphorylation.
C)genes whose products are used in translation of mRNA.
D)ribosomal genes.
E)All of the items listed are correct.

Question 63

You breed a black,long-haired rabbit with a white,short-haired rabbit.All of the offspring have long,black hair.If the genes for hair color and length are closely linked on the same chromosome,what would you expect to see in the F₂ generation?

A)15 black,long-haired: 1 black,short-haired: 1 white,long-haired: 5 white,short-haired
B)3 black,long-haired: 1 white,short-haired
C)9 black,long-haired: 3 black,short-haired: 3 white,long-haired: 1 white,short-haired
D)3 black,long-haired: 9 black,short-haired: 9 white,long-haired: 1 white,short-haired
E)All long-haired black

Question 64

Shown below is a map of five genes,E,L,V,I,and S,on a chromosome.The map units between each gene are shown (map units are a measure of the distance between two genes on a chromosome).Which of the following pairs would have the highest frequency of recombination?
E----5----L-2-V-------10-------I--------------20---------------S

A)I and S
B)V and I
C)E and L
D)L and V
E)L and S

Question 65

A modification of a gene or chromosome that occurs during gamete formation or early development that permanently alters the expression of that gene for the lifetime of the individual is called

A)maternal effect
B)epigenetic inheritance
C)epistasis
D)extranuclear inheritance
E)sex-linked inheritance

Question 66

In plants,most chloroplasts are inherited from the maternal plant because maternal gametes contribute the most __________ to the zygote.

A)cytoplasm
B)mitochondria
C)ribosomes
D)chlorophyll
E)cytoplasm and mitochondria

Question 67

If a plant species exhibits maternal inheritance for leaf pigmentation,what is the phenotype of the parents of a variegated (green and white leaves)plant?

A)The maternal plant must be white and the paternal plant must be green.
B)The maternal plant must be green and the paternal plant must be white.
C)The maternal plant must be variegated and the paternal plant can be any color.
D)Both the maternal and paternal plant must be variegateD.
E)The maternal plant must be variegated and the paternal plant must be whitE.

Question 68

A gene for sweat gland production is located on the X chromosome.A man who lacks sweat glands marries a woman who has normal sweat glands.Which of the following are possible phenotypes of their children?

A)All of the boys will lack sweat glands.
B)The boys will be mosaic;they will have patches of skin with sweat glands and patches of skin lacking sweat glands
C)Half of the girls will have sweat glands and half of the girls will lack sweat glands
D)Half of the boys will have sweat glands and half of the boys will lack sweat glands
E)The girls will be mosaic;they will have patches of skin with sweat glands and patches of skin lacking sweat glands

Question 69

You see a recombination frequency of 0.3%.What does this indicate?

A)That the genes are located close together on the same chromosome
B)That the genes are on different chromosomes
C)That the genes are assorting independently most of the time
D)That the offspring has a large number of non-parental phenotypes
E)That the genes are located on the same chromosome,but very far apart

Question 70

You are trying to improve growth in an economically important fish species.These fish have a gene that controls their size.There are two size alleles;L and S.You cross a large female (LL)with a small male (SS)and get all large fish! The genotypes of the F₁ are 100% LS so you assume that large size is dominant to small.You then cross a small female (SS)with a large male (LL)and get all small fish! The genotypes of this F₁ are all LS.How do you explain this result?

A)The gene for large size is a maternal effect gene.
B)L is not dominant to S.
C)The gene for large size is a sex-linked gene.
D)L is dominant to S.
E)The gene for large size is a maternal effect gene and L is dominant to S.

Question 71

A plant cell contains _____ genomes and an animal cell contains ______ genomes.

A)3,2
B)3,3
C)2,3
D)2,2
E)1,1

Question 72

The Xist gene product

A)is never translated into protein.
B)is required for the production of Barr bodies.
C)coats the X chromosome with RNA.
D)associates with proteins to compact the chromosome.
E)All of these statements are correct.

Question 73

A man has a mutation in a mitochondrial gene encoding a subunit of the ATP synthase complex.The mutation leads to a defective ATP synthase that is not able to synthesize ATP effectively,and this in turn leads to extreme muscle weakness in the affected individual.If this man has children,what is the likelihood that they will inherit this disease from him?

A)100%
B)0%
C)50%
D)25%
E)75%

Question 74

Epigenetic inheritance

A)only refers to autosomal genes.
B)only effects female offspring.
C)only effects male offspring.
D)can result in the expression of different alleles in different generations.
E)only refers to X inactivation.

Question 75

In cats,the gene for coat color is found on the X chromosome.Shown below is a mass of cells making up an early female cat embryo.The X chromosomes are shown in each cell;this embryo has one orange coat color allele (O)and one black coat color allele (B).Which of the following is ACCURATE about this embryo?

A)It will give rise to a calico cat
B)It will give rise to a black cat,because black is dominant to orange
C)It will give rise to an orange cat,as the paternal chromosomes carrying the black allele will be inactivated
D)Since it is heterozygous,it will give rise to a cat with two Barr bodies in each cell
E)Since it is heterozygous,it will give rise to a calico cat with two Barr bodies in each cell

Question 76

Assume that in watermelon plants the genes for flower color (Y = yellow;y = orange flowers)and fruit shape (R = round;r = oval)are on the same chromosome.You cross two true-breeding plants,one with yellow flowers and round fruit and the other with orange flowers and oval fruit.You take one of the F₁ individuals and cross it with a plant that is homozygous recessive for both traits.You get the following in the F₂: 300 yellow flowers,round fruit;300 orange flowers,oval fruit;100 yellow flowers,oval fruit,100 orange flowers,round fruit.
The recombination frequency observed in experimental crosses can be used to indicate distances between genes on a chromosome.More specifically,the map distance between two genes is equal to the frequency of recombinant offspring.What is the map distance between the genes for flower color and fruit shape?

A)25.0
B)4.0
C)40.0
D)33.0
E)100.0

Question 77

The inheritance pattern in which the mother provides gene products to the developing egg cells is called

A)X inactivation.
B)extranuclear inheritance.
C)genomic imprinting.
D)linkage.
E)maternal effects.

Question 78

Which of the following diseases is not caused by a mutation in a mitochondrial gene?

A)Leber's Inherited Optic Neuropathy (LHON)
B)Neurogenic muscle weakness
C)myoclonic epilepsy
D)cardiomyopathy
E)Turner syndrome

Question 79

Extranuclear inheritance was first described by Carl Correns based on his observations of Mirabilis jalapa (the four o'clock plant).M.jalapa can have either white,variegated (white and green)or green leaves.Pollen from a variegated M.jalapa plant is used to fertilize a white M.jalapa flower.Which of the following phenotypes would you expect to see in the offspring of this cross?

A)White
B)Green
C)Variegated
D)White and variegated
E)White,green,and variegated

Question 80

You are mapping the location of two genes in Drosophila,listless l and blind b.(l⁺ l⁺ b⁺ b⁺)and (l⁺ l b⁺ b)flies are normal,but (l l b b)flies don't move around very much and cannot detect the location of a light source.You perform a cross between a true-breeding normally active,sighted fly and a true-breeding listless,blind fly.You testcross an F1 individual with an individual homozygous recessive for both traits and get the following results:
Listless,sighted: 100
Listless,blind: 400
Normal activity,sighted: 400
Normal activity,blind: 100
The recombination frequency observed in experimental crosses can be used to indicate distances between genes on a chromosome.More specifically,the map distance in map units between two genes is equal to the frequency of recombinant offspring.What is the distance between these two genes?

A)They are on different chromosomes.
B)They are 10 map units apart.
C)They are 20 map units apart.
D)They are 40 map units apart.
E)They are 80 map units apart.