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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

F) A) and B)
G) A) and D)

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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

E) All of the above
F) A) and B)

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

A) True
B) False

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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.

F) A) and E)
G) A) and B)

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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

F) A) and D)
G) A) and B)

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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

F) C) and E)
G) B) and E)

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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 ( α\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 α\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

F) All of the above
G) D) and E)

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The agouti gene,when expressed in mice,makes them obese,ravenous,yellow,and prone to diabetes.The agouti phenotype is dominant.During ovulation an agouti mouse is given a drug that methylates (or shuts off the agouti gene) .She is then bred to another mouse and gives birth to a litter of baby mice,none of whom have the agouti phenotype.Which of the following is accurate?


A) an epigenetic change in the mother was passed to her offspring
B) her offspring inherit the methylated form of the agouti gene
C) the agouti gene will be inactivated for the entire lives of her offspring
D) all of these are correct

E) C) and D)
F) None of the above

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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.

F) C) and D)
G) D) and E)

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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%

F) A) and B)
G) A) and C)

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In cats,a fur color gene is on the X chromosome.At this locus,cats can have a black allele or an orange allele.Cats who are homozygous for the black allele have black fur,cats who are homozygous for the orange allele have orange fur,and cats who are heterozygous at this locus are tortoiseshell.What offspring would you expect from a cross between an orange female and a black male?


A) orange females and black males
B) black females and orange males
C) tortoiseshell females and orange males
D) tortoiseshell females and black males
E) tortoiseshell females and tortoiseshell males

F) A) and B)
G) A) and C)

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Which of the following is evidence supporting the Lyon hypothesis of X inactivation?


A) Female mammals that are heterozygous for X-linked traits are phenotypic mosaics.
B) A highly condensed structure is consistently observed in female cells,but not in normal male cells.
C) A female cat that is homozygous for coat color cannot have a calico phenotype.
D) Calico patterns of coat color are never exactly the same.
E) All of these are correct

F) None of the above
G) A) and B)

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Barr bodies


A) are formed in females
B) are formed only in males
C) cause an increased production of X-linked gene products
D) inactivate Xic on autosomes
E) are formed only in males and inactivate Xic on autosomes

F) None of the above
G) A) and C)

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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

E) B) and D)
F) C) and D)

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

A) True
B) False

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A mitochondrion has its own genome,so it can live independently from a eukaryotic cell.

A) True
B) False

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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.

F) C) and E)
G) C) and D)

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Paternal inheritance occurs in plants but not animals because plants have chloroplasts instead of mitochondria.

A) True
B) False

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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

F) C) and D)
G) B) and C)

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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

F) All of the above
G) A) and B)

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