Pedigree Flashcard

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 an individual is heterozygous?

Back

An individual is heterozygous if they have two different alleles for a particular gene, one inherited from each parent (e.g., Bb).

Front

What does it mean if an individual is homozygous?

Back

An individual is homozygous if they have two identical alleles for a particular gene, either dominant (BB) or recessive (bb).

Front

What is the probability of a child inheriting a recessive trait if both parents are carriers?

Back

If both parents are carriers (Bb), there is a 25% chance that their child will inherit the recessive trait (bb).

Front

How can you determine the number of males in a pedigree chart?

Back

Count the squares in the pedigree chart, as squares represent males.

Front

What does a half-shaded symbol in a pedigree represent?

Back

A half-shaded symbol indicates that the individual is a carrier of the trait (heterozygous) but does not express the trait.

Front

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

Back

The first generation in a pedigree chart is crucial as it establishes the starting point for tracking the inheritance of traits through subsequent generations.

Front

How do you calculate the chances of a child having a specific trait?

Back

To calculate the chances, use a Punnett square to determine the possible allele combinations from the parents.

Front

What does it mean if a trait is dominant?

Back

A dominant trait is one that will be expressed in the phenotype if at least one dominant allele is present (e.g., BB or Bb).

Front

What is the role of carriers in genetic inheritance?

Back

Carriers have one copy of a recessive allele and can pass it on to their offspring without expressing the trait themselves.