Chapter 13 Chromosomal Basis of Inheritance, and Human Genetics Flashcards
The term sex chromosomes refer to a distinctive pair of chromosomes that vary between ___
and ___
individuals.
XY and XX
male and female
The
____chromosomes are a pair of chromosomes that are different in males and females.
sex
In male Drosophila flies, the Y chromosome pairs with which of the following during meiosis?
Multiple choice question.
The X chromosome
The other Y chromosome
Nothing
The X chromosome
In Drosophila melanogaster, which of the following sex chromosomes are found in a female?
Multiple choice question.
XX
ZW
XO
XY
XX
Morgan’s experiments revealed that eye color alleles in fruit flies are located on one of the sex chromosomes, more specifically, the
_____ chromosome.
X
What is a sex-linked trait?
Multiple choice question.
A trait that occurs only in females and never in males.
A trait that occurs only in males and never in females.
A trait determined by a gene on the X chromosome.
A trait determined by a gene on the X chromosome.
What is an autosome?
Multiple choice question.
Any chromosome found in a eukaryote
Any chromosome that is not a sex chromosome
Any chromosome that does not have a homologue
Any chromosome that has a homologue
Any chromosome that is not a sex chromosome
The term sex chromosomes refer to a distinctive pair of chromosomes that vary between
___ and ___ individuals
XX and XY
What is the purpose of dosage compensation?
Multiple choice question.
It ensures that males and females have the same number of chromosomes.
It ensures that males and females have the same number of genes.
It ensures that males and females express X-linked traits (proteins) at equal levels.
It ensures that males and females express X-linked traits (proteins) at equal levels.
____ is the term for any chromosome that is not a sex chromosome.
autosome
A human male with a recessive allele for a particular trait on the X chromosome is neither homozygous or heterozygous, but is instead referred to as
____
hemizygous
Question Mode
Fill in the Blank Question
Fill in the blank question.
A highly condensed X chromosome is known as a(n)
___
body.
barr
Morgan’s experiments revealed that eye color alleles in fruit flies are located on one of the sex chromosomes, more specifically, the ____
chromosome.
X
In eukaryotic cells, in addition to the nucleus,
____
and
____
contain their own genetic material.
mitochondria chloroplasts
What ensures that females do not produce twice as much of the proteins encoded by genes on the X chromosome as males produce?
Multiple choice question.
Crossing over
Aneuploidy
Dosage compensation
Dosage compensation
Which X chromosome is inactivated in a female mammal?
Multiple choice question.
Either X chromosome may be inactivated. The choice is random.
The X chromosome inherited from the mother is always inactivated.
The X chromosome inherited from the father is always inactivated.
Either X chromosome may be inactivated. The choice is random.
What is a Barr body?
Multiple choice question.
An imprinted gene only found in females
A maternal cell that transports gene products into the developing egg
A highly condensed X chromosome
A region on the X chromosome that is essential for compaction
A highly condensed X chromosome
Why do mitochondrial genes fail to display Mendelian inheritance patterns?
Multiple choice question.
Mitochondria are not partitioned with the nucleus during meiosis.
Mitochondria are not found in females
Mitochondria are not found in males.
The mitochondrial genome is inactivated in males.
Mitochondria are not partitioned with the nucleus during meiosis.
Question Mode
Fill in the Blank Question
Fill in the blank question.
In humans, mitochondria are inherited through a type of uniparental inheritance called
____
inheritance.
maternal
What mechanism ensures that males and females produce the same amount of the proteins encoded by X-linked genes despite having different numbers of X chromosomes?
Multiple choice question.
Aneuploidy
Crossing over
Dosage compensation
Nondisjunction
Dosage compensation
Which of the following is a disease caused by mutation in human mitochondrial genes that affects the optic nerve, leading to vision loss in one or both eyes?
Multiple choice question.
Myoclonic epilepsy and ragged-red muscle fibers
Neurogenic muscle weakness
Maternal myopathy and cardiopathy
Leber’s hereditary optic neuropathy
Leber’s hereditary optic neuropathy
What determines which X chromosome will be inactivated in a human female?
Multiple choice question.
The X chromosome containing more mutations is inactivated.
A random X chromosome is inactivated.
The X chromosome inherited from the father is always inactivated.
A random X chromosome is inactivated.
Which of the following types of genes are not inherited according to Mendel’s laws?
Multiple select question.
Genes on the Y chromosome
Chloroplast genes
Mitochondrial genes
Genes on the X chromosome
Chloroplast genes
Mitochondrial genes
In humans and other mammals, albinism is a simple, Blank______ trait.
Multiple choice question.
incompletely dominant
dominant
recessive
recessive
How are mitochondria inherited in humans?
Multiple choice question.
Biparental inheritance
Maternal inheritance
Mendelian inheritance
Epigenetic inheritance
Paternal inheritance
Maternal inheritance
Hemophilia is caused by which of the following?
Multiple choice question.
An X-linked dominant allele
An autosomal dominant allele
An autosomal recessive allele
An X-linked recessive allele
An X-linked recessive allele
In a human pedigree, males are symbolized with
____, while females are symbolized with
____
. Symbols for individuals showing the trait are shaded.
squares and circles
Which of the following conditions is inherited due to a dominant allele?
Multiple choice question.
Albinism
Juvenile glaucoma
Hemophilia
Cystic fibrosis
Juvenile glaucoma
What is the hallmark of a recessive autosomal pedigree?
Multiple choice question.
Two unaffected parents can have an affected offspring.
Affected offspring always have at least one affected parent.
The trait is equally distributed among males and females.
Reason: This is true for any autosomal pedigree (recessive or dominant) and is therefore not the hallmark of a recessive autosomal pedigree.
Two unaffected parents will never have affected offspring.
Two unaffected parents can have an affected offspring.
Which of the following human genetic disorders display sex linkage?
Multiple choice question.
Sickle-cell anemia
Phenylketonuria
Down syndrome
Hemophilia
Hemophilia
A male with hemophilia has
____
X chromosome(s) containing the hemophilia allele, and a female with hemophilia has
___
X chromosome(s) with the hemophilia allele (please enter numbers).
1 and 2
Pedigree analysis is typically used for studying Blank______.
Multiple choice question.
plant traits that follow simple inheritance
human traits with complex inheritance patterns that may not follow simple Mendelian rules
human traits that follow simple inheritance patterns
human traits that follow simple inheritance patterns
For a condition that is caused by an X-linked recessive allele, which of the following parents can have affected daughters?
Multiple choice question.
An affected mother and an unaffected father
A homozygous unaffected mother and an affected father
A mother that is a carrier and an affected father
A mother that is a carrier and an affected father
Answer Mode
Multiple Choice QuestionYour Answer correct
What causes sickle-cell anemia?
Multiple choice question.
A mutation in a protein-coding gene
Monosomy for chromosome 15
Inheritance of a deletion in an imprinted gene
Trisomy for chromosome 22
A mutation in a protein-coding gene
What are the effects of sickle cell anemia?
Multiple select question.
Accumulation of mucus in the lungs
Changes in red blood cell shape
Impaired oxygen delivery to tissues
Deterioration of the central nervous system during infancy
Changes in red blood cell shape
Impaired oxygen delivery to tissues
The sickle cell allele is prevalent in populations that are descendants of which of the following groups of individuals?
Multiple choice question.
Native American
African
Western European
Asian
Eastern European
African
Answer Mode
Multiple Choice QuestionYour Answer correct
For conditions caused by X-linked alleles, sons Blank______.
Multiple choice question.
always inherit the condition from their mothers
can inherit the condition either from their fathers or their mothers
always inherit the condition from their fathers
always inherit the condition from their mothers
Answer Mode
Multiple Choice QuestionYour Answer correct
Why is the sickle cell allele prevalent in people of African descent?
Multiple choice question.
Because an allele of a different gene that is also common in people of African descent compensates for the mutation
Because oxygen levels are very high in Africa, making anemia less likely
Because the sickle cell allele confers resistance to malaria
Because the sickle cell allele confers resistance to malaria
Question Mode
Multiple Choice Question
Clumping of red blood cells and interference with blood circulation are symptoms of which genetic disorder?
Multiple choice question.
Sickle cell anemia
Down syndrome
Huntington’s disease
Cystic fibrosis
Sickle cell anemia
Answer Mode
Multiple Choice QuestionYour Answer correct
How are the prevalences of malaria and sickle cell anemia in central regions of Africa related?
Multiple choice question.
Regions that have high prevalence of malaria exhibit high prevalence of the sickle cell anemia trait.
Regions that have low prevalence of malaria exhibit high prevalence of the sickle cell anemia trait.
Regions that have intermediate prevalence of malaria exhibit high prevalence of the sickle cell anemia trait.
Regions that have high prevalence of malaria exhibit high prevalence of the sickle cell anemia trait.
Which genetic disorders are inherited in an autosomal (not X- or Y-linked) dominant fashion?
Multiple select question.
Cystic fibrosis
Huntington disease
Hypercholesterolemia
Down syndrome
Reason: Down syndrome is not inherited in a dominant/recessive fashion. In Down syndrome there are no dominant or recessive alleles, rather, an entire extra chromosome is found.
Tay-Sachs disease
Huntington disease
Hypercholesterolemia
What inheritance pattern is displayed by Duchenne’s muscular dystrophy?
Multiple choice question.
X-linked dominant
Autosomal (not X- or Y-linked) recessive
X-linked recessive
Autosomal (not X- or Y-linked) dominant
X-linked recessive
What term describes the failure of homologous chromosomes or sister chromatids to separate during meiosis?
____
nondisjunction
What is the hallmark of a recessive autosomal pedigree?
Multiple choice question.
Two unaffected parents will never have affected offspring.
Two unaffected parents can have an affected offspring.
Affected offspring always have at least one affected parent.
The trait is equally distributed among males and females.
Reason: This is true for any autosomal pedigree (recessive or dominant) and is therefore not the hallmark of a recessive autosomal pedigree.
Two unaffected parents can have an affected offspring.
What is aneuploidy?
Multiple choice question.
The process that inactivates X chromosomes
The mechanism that leads to nondisjunction
The gain or loss of a chromosome
A change in gene expression based on parental origin
The gain or loss of a chromosome
Question Mode
Fill in the Blank Question
Fill in the blank question.
Both hypercholesterolemia and Huntington disease display an autosomal (not X- or Y-linked)
____
inheritance pattern.
dominant
____ is a term which describes the type of aneuploidy in which an individual is missing one copy of an autosome
monosomy
What is nondisjunction?
Multiple choice question.
A break in a chromosome
Failure of homologues or sister chromatids to separate properly during meiosis
Premature separation of sister chromatids during meiosis
Movement of a segment of one chromosome to a non-homologous chromosome
Failure of homologues or sister chromatids to separate properly during meiosis
An individual who has gained an extra autosome is referred to as which of the following?
Multiple choice question.
Triploid
Monosomic
Imprinted
Trisomic
Trisomic
Which human autosomes can be present in three copies (trisomy) and still allow the individuals to survive (at least for some time after birth)?
Multiple choice question.
All of the autosomes
Only the 5 largest autosomes
Only 5 of the smallest autosomes
None of the autosome
Only 5 of the smallest autosomes
Nondisjunction can lead to the gain or loss of a chromosome. What is the name of this condition? ___
aneuploidy
Phenylketonuria and sickle cell anemia are described as which of the following?
Multiple choice question.
X-linked disorders
Y-linked disorders
Autosomal (not X- or Y-linked) recessive disorders
Autosomal (not X- or Y-linked) dominant disorders
Autosomal (not X- or Y-linked) recessive disorders
____ is the movement of a portion of one chromosome to a non-homologous chromosome.
Field 1: Translocation
Question Mode
Multiple Choice Question
The loss of one copy of an autosome is called which of the following?
Multiple choice question.
X inactivation
Monosomy
Trisomy
Dosage compensation
Monosomy
Question Mode
Fill in the Blank Question
Fill in the blank question.
The risk of Down syndrome increases with the
____
of the mother.
age
Question Mode
Fill in the Blank Question
Fill in the blank question.
A
____
is the type of aneuplody in which an individual has gained an extra autosome.
trisomy
Answer Mode
Multiple Choice QuestionYour Answer correct
In humans, gametes produced by females are more frequently affected by chromosomal abnormalities (such as disjunction, or translocation). What explains that observation?
Multiple choice question.
Cells destined to produce female gametes undergo more than one meiotic divisions, which increases the chance of chromosomal abnormalities.
Female gametes are less protected from environmental stress, which increases the chance of chromosomal mutations.
Female gametes are set aside during embryonic development and arrested in meiosis I with paired homologues.
Female gametes are set aside during embryonic development and arrested in meiosis I with paired homologues.
Answer Mode
Multiple Choice QuestionYour Answer correct
Which of the following describes most human trisomies?
Multiple choice question.
They are not lethal, but are associated with disease.
They are lethal.
They are not associated with disease.
They are lethal.
When can nondisjunction in human sex chromosomes occur?
Multiple choice question.
Only female meiosis
Both male and female meiosis
Only male meiosis
Both male and female meiosis
Question Mode
Multiple Choice Question
How many Barr bodies will be present in the cells of an XXX individual?
Multiple choice question.
1
2
3
2
Question Mode
Multiple Choice Question
The risk of giving birth to a child with Down syndrome increases with which of the following?
Multiple choice question.
The age of the mother
The number of Barr bodies the mother has
The age of the father
The number of children the mother has had
The age of the mother
Answer Mode
Multiple Choice QuestionYour Answer correct
What sex chromosome genotype is associated with Jacob syndrome?
Multiple choice question.
XXY
XO
XYY
correct
XXX
XYY
____ is the movement of a portion of one chromosome to a non-homologous chromosome.
translocation
What phenotypes are associated with Turner syndrome?
Multiple select question.
Tall stature
Diminished mental capacity
Immature sex organs
Webbed neck
Immature sex organs
Webbed neck
Answer Mode
Multiple Choice QuestionYour Answer correct
An individual with a XXY genotype displays a condition known as Blank______.
Multiple choice question.
Jacob syndrome
Down syndrome
Turner syndrome
Kleinfelter syndrome
Kleinfelter syndrome
Answer Mode
Fill in the Blank QuestionYour Answer correct
Fill in the blank question.
During an
_____, a needle is inserted into the mother’s uterus and a small sample of amniotic fluid is removed. The baby’s cells are then grown as a tissue culture for analysis.
amniocentesis
Answer Mode
Multiple Choice QuestionYour Answer correct
What sex chromosome combination is associated with Turner syndrome?
Multiple choice question.
XO
XYY
XXY
XX
XO
Answer Mode
Multiple Choice QuestionYour Answer correct
What is the purpose of genetic counseling?
Multiple choice question.
To predict the risk of genetic defects
To determine an individual’s DNA sequence
To determine the prevalence of genetic disease
To compare DNA sequences among individuals of different ethnic backgrounds
To predict the risk of genetic defects
Which of the following is a noninvasive method that allows screening for certain conditions, such as Down syndrome?
Multiple choice question.
Chorionic villus sampling
cfDNA
Amniocentesis
Genome-wide association
cfDNA
In CVS cells are removed from the chorion. The chorion is found where?
Multiple choice question.
Outer lining of the uterus
Membranous part of the placenta
correct
Amniotic fluid
Inner lining of the uteru
Membranous part of the placenta
Answer Mode
Multiple Choice QuestionYour Answer correct
Noninvasive prenatal methods are based on the presence of Blank______.
Multiple choice question.
fetal DNA in the urine
paternal DNA in maternal blood plasma
fetal DNA in maternal blood plasma
fetal DNA in maternal blood plasma
If nondisjunction occurs during the formation of oocytes, which of the following gametes can be formed?
Multiple select question.
no X chromosomes
XY
X
XX
XX
no X chromosomes
