Pedigree Practice

Front

What is a pedigree?

Back

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

Front

What does it mean if a trait is autosomal recessive?

Back

An autosomal recessive trait requires two copies of the recessive allele (hh) for the trait to be expressed. Individuals with one dominant allele (Hh) are carriers but do not express the trait.

Front

What is the genotype of an affected individual in an autosomal recessive disorder?

Back

hh (homozygous recessive).

Front

How can you determine the relationship between individuals in a pedigree?

Back

By analyzing their connections and the symbols used in the pedigree, such as squares for males and circles for females.

Front

What shape represents a female in a pedigree?

Back

Circle.

Front

What does a filled shape in a pedigree indicate?

Back

A filled shape indicates that the individual is affected by the trait being studied.

Front

What does a half-filled shape in a pedigree represent?

Back

A half-filled shape indicates that the individual is a carrier of the trait but is not affected.

Front

What is the significance of the generation number in a pedigree?

Back

The generation number helps to identify the lineage and the relationships between individuals across generations.

Front

What is the genotype of a carrier for an autosomal recessive disorder?

Back

Bb (heterozygous).

Front

How do you identify siblings in a pedigree?

Back

Siblings are connected by a horizontal line that connects their parents, and they are represented by shapes that are aligned vertically.