Pedigrees

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.

Front

What do we use pedigrees for?

Back

To track traits in families.

Front

How many alleles does a child get from each parent for a trait?

Back

1.

Front

What does a shaded square represent in a pedigree diagram?

Back

An affected male.

Front

What does a shaded circle represent in a pedigree diagram?

Back

An affected female.

Front

What is a carrier in a pedigree chart?

Back

An individual who does not have the trait but can pass it on.

Front

What does it mean if a trait skips a generation in a pedigree?

Back

It may indicate that the trait is recessive.

Front

What does it mean if a trait appears in every generation in a pedigree?

Back

It may indicate that the trait is dominant.

Front

What is the difference between dominant and recessive traits?

Back

Dominant traits require only one allele to be expressed, while recessive traits require two alleles.

Front

What is a phenotype?

Back

A phenotype is the observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.