(MIDTERM) Cytogenetics - OCTOBER 3, 2025 (IV)

A

What is the primary purpose of a pedigree chart?

A. To show how a particular trait or genetic disorder is passed down through generations of a family.

B. To measure the height and weight of family members.

C. To record the birth dates of all living relatives.

D. To track the financial assets inherited by a family.

A

In a pedigree chart, what standardized symbol represents a male family member?

A. A square.

B. A diamond.

C. A circle.

D. A triangle.

B

What standardized symbol represents a female family member in a pedigree chart?

A. A square.

B. A circle.

C. A rectangle.

D. A hexagon.

C

What does a shaded square in a pedigree chart indicate?

A. An unaffected male.

B. A male who is a carrier.

C. An affected male.

D. A deceased male.

B

What does a shaded circle in a pedigree chart indicate?

A. A female who is a carrier.

B. An affected female.

C. An unaffected female.

D. A female with unknown status.

D

What does a half-shaded square or circle typically represent in a pedigree chart?

A. An affected individual.

B. A person who is deceased.

C. An individual whose gender is unknown.

D. A carrier (heterozygous for the trait).

D

Which term is used to describe a pedigree chart?

A. A timeline of historical events.

B. A diagram of cellular structure.

C. A geological map.

D. A family tree that tracks how traits are inherited.

C

What does a horizontal line connecting a male and a female symbol represent in a pedigree chart?

A. A sibling relationship.

B. A parent-child relationship.

C. Marriage (or mating).

D. A business partnership.

B

What indicates the children of a couple in a pedigree chart?

A. A horizontal line above the couple.

B. A bracket or vertical line extending below the couple.

C. A diagonal line across the couple.

D. A double horizontal line.

C

What do Roman numerals (I, II, III, etc.) typically represent in a pedigree chart?

A. The number of children in a family.

B. The birth order of individuals.

C. Generations in the family.

D. The chromosome number being studied.

C

In the provided example, who are the parents of Jose, Alex, and Lucy?

A. Lucy and Steve.

B. Hannah and Brenda.

C. Mary and Carlos.

D. Alex and Jose.

B

In the example chart, Mary is represented by a circle, and Carlos is represented by a square. What does this show?

A. They are siblings.

B. They are spouses and represent female and male, respectively.

C. They are both affected by the trait.

D. They are from different countries.

D

Which statement describes a trait inherited as a dominant trait?

A. It skips one or more generations.

B. It requires two copies of the allele to be expressed.

C. It appears mostly in males.

D. There is someone affected in every generation.

A

Why is a trait with an affected individual in every generation considered dominant?

A. Only one copy of the dominant allele is needed for the individual to show the trait.

B. Two copies of the allele are needed to show the trait.

C. The gene is located on a sex chromosome.

D. The trait is linked to environmental factors.

B

Which statement describes a trait inherited as a recessive trait?

A. It is seen in every generation.

B. The trait skips a generation.

C. It appears only when an individual inherits one copy of the allele.

D. It affects males and females equally.

D

When does a recessive trait appear in an individual?

A. When the individual inherits only one copy of the recessive allele.

B. When the individual is a carrier.

C. When the trait is sex-linked.

D. When an individual inherits two copies of the recessive allele (one from each parent).

D

What is the pattern of inheritance if a trait disappears in one generation and reappears later?

A. Dominant.

B. Autosomal.

C. Sex-linked.

D. Recessive.

C

What does it suggest about a trait if it appears mostly in males (squares)?

A. It is dominant.

B. It is autosomal.

C. It is sex-linked, specifically X-linked recessive.

D. It is recessive, but not sex-linked.

C

A trait that appears mostly in males is often X-linked recessive because:

A. Males have two X chromosomes.

B. Females are typically unaffected.

C. Males have only one X chromosome, so if it carries the trait, they express it.

D. The trait is always lethal for females.

B

For an X-linked recessive trait, what role do females often play?

A. They are usually affected by the trait.

B. They are usually carriers and pass the trait to their sons.

C. They are always free of the allele.

D. They are only affected if the trait is dominant.

C

A trait that affects both males and females equally is described as which type of inheritance?

A. Sex-linked.

B. X-linked recessive.

C. Autosomal.

D. Y-linked.

B

An autosomal trait means the gene is located on which type of chromosome?

A. An X chromosome.

B. One of the autosomes (non-sex chromosomes).

C. A Y chromosome.

D. An independently-inherited plasmid.

B

What does it mean if an inheritance is autosomal?

A. Inheritance is related to gender.

B. Inheritance is not related to gender.

C. The trait is always dominant.

D. The trait is only found in females.

C

In the provided example, Lucy and Steve have two daughters. What are their names?

A. Mary and Carlos.

B. Jose and Alex.

C. Hannah and Brenda.

D. Lucy and Steve.

C

If a trait is not skipped across generations, this is a key characteristic of which mode of inheritance?

A. Autosomal recessive.

B. Sex-linked recessive.

C. Dominant

D. Recessive