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Father has a trait, which is inherited in autosomal recessive mode of inheritance.
Calculate the probability to have a son with a trait in marriage with a female who is
a carrier of recessive allele.
Father has a trait, which is inherited in autosomal recessive mode of inheritance. Calculate the probability to have a son with a trait in marriage with a female who is a carrier of recessive allele.
What is a Barr body?
What is a Barr body?
A large, three generation family in whom multiple members are affected with a
rare, undiagnosed disease is being studied. Affected males never produce
affected children, but affected females do produce affected children of both sexes
when mate with unaffected males. What is the most likely mode of inheritance?
A large, three generation family in whom multiple members are affected with a rare, undiagnosed disease is being studied. Affected males never produce affected children, but affected females do produce affected children of both sexes when mate with unaffected males. What is the most likely mode of inheritance?
Neurofibromatosis type 1 is one of the most common autosomal dominant
disorders. A heterozygous woman with neurofibromatosis type 1 has an unaffected
partner. Which of the following is correct regarding their children?
Neurofibromatosis type 1 is one of the most common autosomal dominant disorders. A heterozygous woman with neurofibromatosis type 1 has an unaffected partner. Which of the following is correct regarding their children?
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The characteristic indicated by the blackened figures is probably:
both parents and children affected
The characteristic indicated by the blackened figures is probably:
both parents and children affected
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The pedigree chart below is for a family, some of whose members exhibit the
autosomal dominant trait, brown eye color. Brown eyed individuals are indicated
by a dark square or circle. Use the chart to answer the following question: what is
the probability that individual D-3 is Ww?
The pedigree chart below is for a family, some of whose members exhibit the autosomal dominant trait, brown eye color. Brown eyed individuals are indicated by a dark square or circle. Use the chart to answer the following question: what is the probability that individual D-3 is Ww?
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A man who is affected with hemophilia A (X linked recessive) mates with a woman
who is a heterozygous carrier of this disorder. What proportion of the couple's
daughters will be affected, and what proportionof the daughters will be
heterozygous carriers?
A man who is affected with hemophilia A (X linked recessive) mates with a woman who is a heterozygous carrier of this disorder. What proportion of the couple's daughters will be affected, and what proportionof the daughters will be heterozygous carriers?
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In a certain population, the frequency of color-blind males is 1 in 100. Assuming
that the population is in Hardy-Weinberg eqiulibrium at this locus, the frequency of
color-blind females is approximately
In a certain population, the frequency of color-blind males is 1 in 100. Assuming that the population is in Hardy-Weinberg eqiulibrium at this locus, the frequency of color-blind females is approximately
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In humans an extra copy of chromosome 21 typically leads to moderate to severe
mental retardation and sterility, as well as a greater likelihood of heart defects and
other problems. This disorder is known as ____.
In humans an extra copy of chromosome 21 typically leads to moderate to severe mental retardation and sterility, as well as a greater likelihood of heart defects and other problems. This disorder is known as ____.
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Down syndrome is the result of:
Down syndrome is the result of:
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Which genetic condition is revealed in the photos above?
Which genetic condition is revealed in the photos above?
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Fraternal (dizygotic) twins are produced when:
Fraternal (dizygotic) twins are produced when:
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Which of the following conditions are required for a population to be in HardyWeinberg equilibrium?
Which of the following conditions are required for a population to be in HardyWeinberg equilibrium?
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Cystic fibrosis is an autosomal recessive disease. In a population of one hundred
individuals, twenty-five are found to have the disease. Assuming Hardy-Weinberg
equilibrium, what is the percent of the population that are carriers for cystic
fibrosis?
Cystic fibrosis is an autosomal recessive disease. In a population of one hundred individuals, twenty-five are found to have the disease. Assuming Hardy-Weinberg equilibrium, what is the percent of the population that are carriers for cystic fibrosis?
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75% of a given population test positive for Rhesus (Rh) factor. Given that blood
type Rh is a dominant allele, what percentage of this population is homozygous?
75% of a given population test positive for Rhesus (Rh) factor. Given that blood type Rh is a dominant allele, what percentage of this population is homozygous?
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Identical twins can result from:
Identical twins can result from:
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The change in the chromosome depicted in the figure above represents a(n) ____.
chrosome change place
The change in the chromosome depicted in the figure above represents a(n) ____. chrosome change place
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Nondisjunction in Meiosis I results in
Nondisjunction in Meiosis I results in
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which genetic condition is revealed on the photo below?
bild på en bebis problem med ansiktet
which genetic condition is revealed on the photo below? bild på en bebis problem med ansiktet
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Which genetic condition is revealed in the karyotype display shown in the figure
above?
bild på genokaryt
Which genetic condition is revealed in the karyotype display shown in the figure above?
bild på genokaryt
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The polymerase chain reaction or PCR is a technique that
The polymerase chain reaction or PCR is a technique that
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On the following pedigree what is the genotype of the individuals III-1 and III-2?
its pedgree 1 and 2 not affected
On the following pedigree what is the genotype of the individuals III-1 and III-2? its pedgree 1 and 2 not affected
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On the pedigree of autosomal – recessive inheritance what is the genotype of the
individuals III-1 and III-2?
another bild with almost same as other question
On the pedigree of autosomal – recessive inheritance what is the genotype of the individuals III-1 and III-2? another bild with almost same as other question
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Polyploidy refers to:
Polyploidy refers to:
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Sex-linked genes are genes that are
Sex-linked genes are genes that are
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Which genetic condition is revealed by the symptoms shown in the figure above?
bild på feet and head problems
Which genetic condition is revealed by the symptoms shown in the figure above? bild på feet and head problems
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Which genetic condition is revealed in the karyotype display shown in the figure
above?
bilden visar ingen Y chromosome
Which genetic condition is revealed in the karyotype display shown in the figure above?
bilden visar ingen Y chromosome
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In South Africa, variegate porphyria is found in white South Africans at a higher
frequency than would be expected if the population was in Hardy-Weinberg
eqiulibrium. This population originated from a small group of Dutch settlers. The
most likely explanation for the high frequency of variegate in this population is:
In South Africa, variegate porphyria is found in white South Africans at a higher frequency than would be expected if the population was in Hardy-Weinberg eqiulibrium. This population originated from a small group of Dutch settlers. The most likely explanation for the high frequency of variegate in this population is:
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If a father is hemophiliac, hemophiliac will be his son too
If a father is hemophiliac, hemophiliac will be his son too
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The pedigree represents:
The pedigree represents:
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A woman with normal blood clotting mates with a man who also has normal blood
clotting. Their first child is a boy who has hemophilia. Tests show that the child's
hemophilia is X-linked and that he has normal genetic inheritance. You can predict
that if the couple produces more children together, then the odds are that
A woman with normal blood clotting mates with a man who also has normal blood clotting. Their first child is a boy who has hemophilia. Tests show that the child's hemophilia is X-linked and that he has normal genetic inheritance. You can predict that if the couple produces more children together, then the odds are that
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Some patients have a predisposition to developing neurodegenerative disease
due to genetic mutations in the PrPC gene. If a father knows that he has the
mutation, but never develops the disease, and the mother knows she is not a
carrier, what is the probability that their son will develop the disease? Assume that
this disease follows simple Mendelian inheritance patterns.
Some patients have a predisposition to developing neurodegenerative disease due to genetic mutations in the PrPC gene. If a father knows that he has the mutation, but never develops the disease, and the mother knows she is not a carrier, what is the probability that their son will develop the disease? Assume that this disease follows simple Mendelian inheritance patterns.
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The change in the chromosomes depicted in the figure above represents a(n)
The change in the chromosomes depicted in the figure above represents a(n)
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The photo represents agarose gel electrophoresis patterns of ACE gene
polymorphism. Which of the lanes correspond to the genotype D/D?
SE BILDEN
The photo represents agarose gel electrophoresis patterns of ACE gene polymorphism. Which of the lanes correspond to the genotype D/D?
SE BILDEN
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The chromosome on the photo below is:
SE BILDEN
The chromosome on the photo below is: SE BILDEN
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Prenatal diagnosis techniques such as amniocentesis and chorionic villus
sampling remove cells that were produced by an embryo. These cells are then
used
Prenatal diagnosis techniques such as amniocentesis and chorionic villus sampling remove cells that were produced by an embryo. These cells are then used
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A genetic disorder affects three generations of males in a family, but rarely affects
the females. What is one possible cause of this observation?
A genetic disorder affects three generations of males in a family, but rarely affects the females. What is one possible cause of this observation?
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The pedigree chart below is for a family, some of whose members exhibit the
autosomal dominant trait, brown eye color. Brown eyed individuals are indicated
by a dark square or circle. Use the chart to answer the following question: what is
the genotype of individual B-4.
SE BILDEN
The pedigree chart below is for a family, some of whose members exhibit the autosomal dominant trait, brown eye color. Brown eyed individuals are indicated by a dark square or circle. Use the chart to answer the following question: what is the genotype of individual B-4.
SE BILDEN
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The pedigree chart below is for a family, some of whose members exhibit the
autosomal dominant trait, brown eye color. Brown eyed individuals are indicated
by a dark square or circle. Use the chart to answer the following question: what is
the probability that individual D-3 is Ww?
The pedigree chart below is for a family, some of whose members exhibit the autosomal dominant trait, brown eye color. Brown eyed individuals are indicated by a dark square or circle. Use the chart to answer the following question: what is the probability that individual D-3 is Ww?
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Study Notes
Autosomal Recessive Inheritance
- In autosomal recessive inheritance, an individual must inherit two copies of the recessive allele to express the trait.
- A carrier has one copy of the recessive allele and one copy of the dominant allele. They do not express the trait but can pass it on to their offspring.
Barr Bodies
- A Barr body is an inactive X chromosome found in female cells.
- Females have two X chromosomes, but one is randomly inactivated during development.
- The inactivated X chromosome condenses into a Barr body.
Mode of Inheritance
- The mode of inheritance is likely X-linked dominant.
- Affected males never produce affected children, but affected females do produce affected children of both sexes.
- This pattern suggests the trait is carried on the X chromosome and is dominant.
Neurofibromatosis Type 1
- Neurofibromatosis type 1 is a common autosomal dominant disorder.
- Heterozygous individuals have one copy of the dominant allele and express the trait.
- If one parent is heterozygous and the other is unaffected, there is a 50% chance that their children will inherit the dominant allele and express the trait.
Pedigree Analysis
- The probability of individual D-3 being Ww is 100%.
- Individual D-3 has brown eyes, which is the dominant trait.
- They inherited one dominant allele (W) from their mother (B-4) and one recessive allele (w) from their father (C-3).
Hemophilia A
- Hemophilia A is an X-linked recessive disorder.
- If a father has hemophilia A (X-linked recessive) and a mother is a carrier, their sons have a 50% chance of inheriting the disease.
- Their daughters have a 50% chance of being carriers but will not be affected with the disease.
Color Blindness
- Color blindness is an X-linked recessive trait.
- If the frequency of color-blind males is 1 in 100, the frequency of color-blind females is approximately 1 in 10,000.
Down Syndrome
- Down syndrome is a genetic disorder caused by an extra copy of chromosome 21.
- This leads to moderate to severe mental retardation, sterility, and an increased risk of heart defects and other health issues.
Fraternal Twins
- Fraternal twins are produced when two separate eggs are fertilized by two separate sperm.
- They are genetically distinct and have a similar relationship as any other siblings.
Hardy-Weinberg Equilibrium
- Hardy-Weinberg equilibrium occurs when there is no change in allele frequencies from one generation to the next.
- The conditions required are no mutation, no gene flow, random mating, no genetic drift, and no natural selection.
Cystic Fibrosis
- Cystic fibrosis is an autosomal recessive disease.
- If 25% of a population has the disease, then 50% of the population are carriers.
Rhesus (Rh) Factor
- If 75% of a population is Rh positive, then 25% are homozygous recessive for the Rh-negative trait.
Identical Twins
- Identical twins develop from a single fertilized egg that splits into two embryos.
- They share identical DNA and are always of the same sex.
Chromosomal Change
- The change in the chromosome depicted in the figure represents a translocation.
- This is where a piece of one chromosome breaks off and attaches to another.
Nondisjunction in Meiosis I
- Nondisjunction in meiosis I results in gametes with an extra chromosome or missing a chromosome.
- This can lead to disorders such as Down syndrome or Turner syndrome.
Karyotype Display
- The karyotype display shows a missing Y chromosome, which is characteristic of Turner syndrome.
- Turner syndrome is a genetic disorder that affects females and is characterized by short stature, heart defects, and a lack of ovaries.
Polymerase Chain Reaction (PCR)
- Polymerase chain reaction is a technique that amplifies DNA sequences.
- PCR uses primers to target specific DNA sequences and allows for copies of these sequences to be made.
Pedigree Analysis - Autosomal Recessive Inheritance
- In autosomal recessive inheritance individuals need to inherit two recessive alleles to express the trait.
- Individuals III-1 and III-2 are likely carriers (Aa) as they are unaffected but have a child with the trait (III-3).
Polyploidy
- Polyploidy refers to an organism having more than two sets of chromosomes.
- Polyploidy can lead to changes in the organism's phenotype and is common in plants.
Sex-Linked Genes
- Sex-linked genes are genes that are located on the sex chromosomes (X or Y).
Karyotype Display
- The karyotype display shows a missing Y chromosome, which is characteristic of Turner syndrome.
- Turner syndrome is a genetic disorder that affects females and is characterized by short stature, heart defects, and a lack of ovaries.
Variate Porphyria
- Variate porphyria is a genetic disorder that is more common in white South Africans than in other populations.
- This high frequency is likely due to the founder effect, where a small group of individuals from a specific population established a new population.
Hemophilia Inheritance
- Hemophilia is an X-linked recessive disorder.
- If the father has hemophilia, his sons will also have hemophilia.
- This is because sons inherit the Y chromosome from their father and the X chromosome from their mother.
Neurodegenerative Disease
- If a father has the PrPC gene mutation, but does not develop the disease, and the mother is not a carrier, there is a 0% chance that their son will develop the disease.
- This is because the son will only inherit one copy of the PrPC gene mutation from his father, which is not enough to cause the disease.
ACE Gene Polymorphism
- The lane corresponding to the genotype D/D would show two bands on the agarose gel, one for each allele.
Chromosome Identification
- The chromosome photo is a metacentric chromosome.
- Metacentric chromosomes have the centromere located in the middle.
Prenatal Diagnosis
- Prenatal diagnosis techniques such as amniocentesis and chorionic villus sampling analyze the genetic material of a developing fetus.
Observation of Family History
- The observation of a genetic disorder affecting three generations of males, but rarely affecting females, suggests an X-linked recessive inheritance pattern.
- Males only inherit one X chromosome, so they are more likely to express the trait if they inherit the recessive allele.
Pedigree Analysis
- Individual B-4 is likely heterozygous (Ww) because they have brown eyes (dominant trait) but have a child with blue eyes (recessive trait).
- Individual B-4 must have one dominant allele (W) and one recessive allele (w).
Pedigree Analysis
- The probability that individual D-3 is Ww is 100%.
- Individual D-3 has brown eyes, which is the dominant trait.
- They inherited one dominant allele (W) from their mother (B-4) and one recessive allele (w) from their father (C-3).
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Test your understanding of autosomal recessive inheritance with this quiz. Calculate the probability of having a son with a specific trait when one parent is affected and the other is a carrier. Dive deep into the mechanics of inheritance patterns and probabilities.
