Pedigree Practice

Front

What is a pedigree chart?

Back

A pedigree chart is a diagram that shows the occurrence and appearance of phenotypes of a particular gene or organism and its ancestors, used to analyze the inheritance of traits.

Front

What does it mean if a trait is dominant?

Back

A dominant trait is one that is expressed in the phenotype even when only one copy of the allele is present. It masks the effect of a recessive allele.

Front

What does it mean if a trait is recessive?

Back

A recessive trait is one that is only expressed in the phenotype when two copies of the allele are present. It is masked by a dominant allele.

Front

What is an example of a dominant inheritance pattern?

Back

An example of a dominant inheritance pattern is Huntington's disease, where only one copy of the mutated gene is needed for the individual to express the disease.

Front

What is an example of a recessive inheritance pattern?

Back

An example of a recessive inheritance pattern is cystic fibrosis, which occurs when an individual has two copies of the mutated gene.

Front

What is X-linked inheritance?

Back

X-linked inheritance refers to genes located on the X chromosome. Traits associated with X-linked genes can be expressed differently in males and females due to the presence of one X chromosome in males.

Front

How can you identify a dominant trait in a pedigree chart?

Back

A dominant trait typically appears in every generation, and affected individuals have at least one affected parent.

Front

How can you identify a recessive trait in a pedigree chart?

Back

A recessive trait may skip generations, and affected individuals can have unaffected parents who are carriers of the trait.

Front

What is a carrier in genetics?

Back

A carrier is an individual who has one copy of a recessive allele that does not manifest in their phenotype but can be passed on to offspring.

Front

What is the significance of a square in a pedigree chart?

Back

In a pedigree chart, a square represents a male individual.