Pedigree Analysis Question Paper

Unit 2, Chapter 1: Principles of Inheritance and Variation

Total Questions: 50

Section A: Multiple Choice Questions (20 Questions)

Instructions: Choose the best answer for each question.

Which of the following is a key feature of an autosomal dominant inheritance pattern?
- a. The trait skips generations.
- b. The trait appears in every generation.
- c. More males are affected than females.
- d. Affected individuals have unaffected parents.

In an autosomal recessive inheritance pattern, what is the approximate percentage of offspring affected when two carrier parents mate?
- a. 100%
- b. 75%
- c. 50%
- d. 25%

What is a characteristic feature of X-linked dominant inheritance?
- a. Affected fathers pass the trait to all their sons.
- b. Affected fathers pass the trait to all their daughters.
- c. The trait skips generations.
- d. More males are affected than females.

In X-linked recessive inheritance, who are usually the carriers of the trait?
- a. Affected males
- b. Unaffected males
- c. Affected females
- d. Unaffected females (daughters of affected fathers)

If a trait appears in every generation and affects both males and females equally, what is the most likely mode of inheritance?
- a. Autosomal recessive
- b. X-linked recessive
- c. Autosomal dominant
- d. X-linked dominant

What does "consanguinity" in a pedigree chart suggest?
- a. A mating between unrelated individuals.
- b. A high probability of a dominant trait.
- c. A mating between relatives, common in autosomal recessive pedigrees.
- d. A new mutation.

In X-linked dominant inheritance, if an affected mother passes the trait, what is the probability of her offspring being affected?
- a. 100% of daughters
- b. 100% of sons
- c. 50% of offspring, regardless of sex
- d. 25% of offspring

What is the term for an individual who is heterozygous for a recessive trait but does not show the phenotype?
- a. Affected
- b. Carrier
- c. Homozygous
- d. Hemizygous

Which inheritance pattern shows no male-to-male transmission?
- a. Autosomal dominant
- b. Autosomal recessive
- c. X-linked (both dominant and recessive)
- d. Y-linked

If an unaffected individual has an allele for a dominant trait, what would be the outcome?
- a. They would be a carrier.
- b. They would be unaffected.
- c. They would be affected.
- d. This scenario is not possible with complete penetrance.

In a pedigree, what does a horizontal line connecting a square and a circle represent?
- a. Siblings
- b. Mating
- c. Offspring
- d. Deceased individuals

What is the genotype of an individual affected by an autosomal recessive trait?
- a. AA
- b. Aa
- c. aa
- d. XaY

If an affected male has an X-linked recessive trait, from whom did he inherit the allele?
- a. His father
- b. His mother
- c. Both parents
- d. A new mutation

What is the key feature of Y-linked inheritance?
- a. It affects only females.
- b. It is passed from father to all sons.
- c. It skips generations.
- d. It is the most common form of inheritance.

In mitochondrial inheritance, who transmits the trait?
- a. Only males
- b. Only females to all their progeny
- c. Both males and females equally
- d. It is random.

What does a shaded symbol in a pedigree chart represent?
- a. An unaffected individual
- b. An affected individual
- c. A deceased individual
- d. A carrier

If a trait skips generations, which of the following is a possible mode of inheritance?
- a. Autosomal dominant
- b. X-linked dominant
- c. Autosomal recessive
- d. Y-linked

What is the term for the assumption that an individual marrying into a family with a rare trait is not a carrier?
- a. Complete penetrance
- b. Rare-in-population
- c. Not-Y-linked
- d. Hemizygous

In X-linked recessive inheritance, what is the status of all daughters of an affected father (assuming the mother is not a carrier)?
- a. Affected
- b. Unaffected and not carriers
- c. Carriers
- d. 50% are carriers

If an affected individual is heterozygous (Aa) for an autosomal dominant trait, what is the probability of passing the trait to their offspring?
- a. 100%
- b. 75%
- c. 50%
- d. 25%

Section B: True/False Questions (10 Questions)

Instructions: State whether the following statements are true or false.

In autosomal dominant inheritance, affected individuals must have at least one affected parent.

X-linked recessive traits affect more females than males.

An unaffected individual can be a carrier of a dominant trait.

A father can transmit an X-linked gene to his son.

In autosomal recessive inheritance, two unaffected parents can have an affected child.

Y-linked traits are passed from a father to all his daughters.

Mitochondrial DNA is inherited from the father.

In X-linked dominant inheritance, affected fathers pass the trait to all their daughters.

A trait that appears in every generation is likely recessive.

Complete penetrance means that an individual with the disease-causing genotype will always express the phenotype.

Section C: Short Answer Questions (10 Questions)

Instructions: Provide a brief answer to each question.

What are the three simplifying assumptions made in the provided pedigree problems?

What are the five key clues to remember when reasoning about pedigrees?

Explain the difference between autosomal and X-linked inheritance.

What is "criss-cross inheritance"?

Why are males more commonly affected by X-linked recessive traits?

How can you distinguish between autosomal dominant and X-linked dominant inheritance?

What is the genotype of a female carrier for an X-linked recessive trait?

What is the significance of assuming a trait is "rare-in-population"?

What are the key features of mitochondrial inheritance?

What is the genotype of an affected male with an X-linked dominant trait?

Section D: Pedigree Analysis Problems (10 Questions)

Instructions: Analyze the following pedigrees and answer the questions.

Case 1:

[Pedigree chart would be displayed here]

What is the mode of inheritance shown in this pedigree?

What is the genotype of individual I-1?

What is the genotype of individual II-2?

Case 2:

[Pedigree chart would be displayed here]

What is the most likely mode of inheritance in this pedigree?

Can this be an X-linked dominant trait? Why or why not?

What is the genotype of individual III-1?

Case 3:

[Pedigree chart would be displayed here]

What is the mode of inheritance shown in this pedigree?

Why can't this be an autosomal recessive trait?

What is the genotype of individual II-5?

If individual III-2 marries an unaffected man, what is the probability of them having an affected child?

Pedigree Analysis Question Paper

Unit 2, Chapter 1: Principles of Inheritance and Variation

Total Questions: 50

Section A: Multiple Choice Questions (20 Questions)

Instructions: Choose the best answer for each question.

Which of the following is a key feature of an autosomal dominant inheritance pattern?
- a. The trait skips generations.
- b. The trait appears in every generation.
- c. More males are affected than females.
- d. Affected individuals have unaffected parents.

In an autosomal recessive inheritance pattern, what is the approximate percentage of offspring affected when two carrier parents mate?
- a. 100%
- b. 75%
- c. 50%
- d. 25%

What is a characteristic feature of X-linked dominant inheritance?
- a. Affected fathers pass the trait to all their sons.
- b. Affected fathers pass the trait to all their daughters.
- c. The trait skips generations.
- d. More males are affected than females.

In X-linked recessive inheritance, who are usually the carriers of the trait?
- a. Affected males
- b. Unaffected males
- c. Affected females
- d. Unaffected females (daughters of affected fathers)

If a trait appears in every generation and affects both males and females equally, what is the most likely mode of inheritance?
- a. Autosomal recessive
- b. X-linked recessive
- c. Autosomal dominant
- d. X-linked dominant

What does "consanguinity" in a pedigree chart suggest?
- a. A mating between unrelated individuals.
- b. A high probability of a dominant trait.
- c. A mating between relatives, common in autosomal recessive pedigrees.
- d. A new mutation.

In X-linked dominant inheritance, if an affected mother passes the trait, what is the probability of her offspring being affected?
- a. 100% of daughters
- b. 100% of sons
- c. 50% of offspring, regardless of sex
- d. 25% of offspring

What is the term for an individual who is heterozygous for a recessive trait but does not show the phenotype?
- a. Affected
- b. Carrier
- c. Homozygous
- d. Hemizygous

Which inheritance pattern shows no male-to-male transmission?
- a. Autosomal dominant
- b. Autosomal recessive
- c. X-linked (both dominant and recessive)
- d. Y-linked

If an unaffected individual has an allele for a dominant trait, what would be the outcome?
- a. They would be a carrier.
- b. They would be unaffected.
- c. They would be affected.
- d. This scenario is not possible with complete penetrance.

In a pedigree, what does a horizontal line connecting a square and a circle represent?
- a. Siblings
- b. Mating
- c. Offspring
- d. Deceased individuals

What is the genotype of an individual affected by an autosomal recessive trait?
- a. AA
- b. Aa
- c. aa
- d. XaY

If an affected male has an X-linked recessive trait, from whom did he inherit the allele?
- a. His father
- b. His mother
- c. Both parents
- d. A new mutation

What is the key feature of Y-linked inheritance?
- a. It affects only females.
- b. It is passed from father to all sons.
- c. It skips generations.
- d. It is the most common form of inheritance.

In mitochondrial inheritance, who transmits the trait?
- a. Only males
- b. Only females to all their progeny
- c. Both males and females equally
- d. It is random.

What does a shaded symbol in a pedigree chart represent?
- a. An unaffected individual
- b. An affected individual
- c. A deceased individual
- d. A carrier

If a trait skips generations, which of the following is a possible mode of inheritance?
- a. Autosomal dominant
- b. X-linked dominant
- c. Autosomal recessive
- d. Y-linked

What is the term for the assumption that an individual marrying into a family with a rare trait is not a carrier?
- a. Complete penetrance
- b. Rare-in-population
- c. Not-Y-linked
- d. Hemizygous

In X-linked recessive inheritance, what is the status of all daughters of an affected father (assuming the mother is not a carrier)?
- a. Affected
- b. Unaffected and not carriers
- c. Carriers
- d. 50% are carriers

If an affected individual is heterozygous (Aa) for an autosomal dominant trait, what is the probability of passing the trait to their offspring?
- a. 100%
- b. 75%
- c. 50%
- d. 25%

Section B: True/False Questions (10 Questions)

Instructions: State whether the following statements are true or false.

In autosomal dominant inheritance, affected individuals must have at least one affected parent.

X-linked recessive traits affect more females than males.

An unaffected individual can be a carrier of a dominant trait.

A father can transmit an X-linked gene to his son.

In autosomal recessive inheritance, two unaffected parents can have an affected child.

Y-linked traits are passed from a father to all his daughters.

Mitochondrial DNA is inherited from the father.

In X-linked dominant inheritance, affected fathers pass the trait to all their daughters.

A trait that appears in every generation is likely recessive.

Complete penetrance means that an individual with the disease-causing genotype will always express the phenotype.

Section C: Short Answer Questions (10 Questions)

Instructions: Provide a brief answer to each question.

What are the three simplifying assumptions made in the provided pedigree problems?

What are the five key clues to remember when reasoning about pedigrees?

Explain the difference between autosomal and X-linked inheritance.

What is "criss-cross inheritance"?

Why are males more commonly affected by X-linked recessive traits?

How can you distinguish between autosomal dominant and X-linked dominant inheritance?

What is the genotype of a female carrier for an X-linked recessive trait?

What is the significance of assuming a trait is "rare-in-population"?

What are the key features of mitochondrial inheritance?

What is the genotype of an affected male with an X-linked dominant trait?

Section D: Pedigree Analysis Problems (10 Questions)

Instructions: Analyze the following pedigrees and answer the questions.

Case 1:

[Pedigree chart would be displayed here]

What is the mode of inheritance shown in this pedigree?

What is the genotype of individual I-1?

What is the genotype of individual II-2?

Case 2:

[Pedigree chart would be displayed here]

What is the most likely mode of inheritance in this pedigree?

Can this be an X-linked dominant trait? Why or why not?

What is the genotype of individual III-1?

Case 3:

[Pedigree chart would be displayed here]

What is the mode of inheritance shown in this pedigree?

Why can't this be an autosomal recessive trait?

What is the genotype of individual II-5?

If individual III-2 marries an unaffected man, what is the probability of them having an affected child?

Pedigree

Pedigree Analysis Question Paper

Section A: Multiple Choice Questions (20 Questions)

Section B: True/False Questions (10 Questions)

Section C: Short Answer Questions (10 Questions)

Section D: Pedigree Analysis Problems (10 Questions)

Case 1:

Case 2:

Case 3:

On this page

Pedigree

Pedigree Analysis Question Paper

Section A: Multiple Choice Questions (20 Questions)

Section B: True/False Questions (10 Questions)

Section C: Short Answer Questions (10 Questions)

Section D: Pedigree Analysis Problems (10 Questions)

Case 1:

Case 2:

Case 3:

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Pedigree

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