Pedigree

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, used to analyze the inheritance of traits.

Front

What does the term 'genotype' refer to?

Back

Genotype refers to the genetic constitution of an individual, specifically the alleles present for a particular gene.

Front

What does the term 'phenotype' refer to?

Back

Phenotype refers to the observable physical characteristics of an organism, which result from the interaction of its genotype with the environment.

Front

What does a filled circle represent in a pedigree chart?

Back

A filled circle represents an affected female.

Front

What does a filled square represent in a pedigree chart?

Back

A filled square represents an affected male.

Front

What does a half-filled square represent in a pedigree chart?

Back

A half-filled square represents a male who is a carrier of the trait.

Front

What does a half-filled circle represent in a pedigree chart?

Back

A half-filled circle represents a female who is a carrier of the trait.

Front

What is the significance of a trait skipping a generation in a pedigree?

Back

If a trait skips a generation, it is an indication that the trait is recessive.

Front

What is an autosomal recessive disorder?

Back

An autosomal recessive disorder is a genetic condition that occurs when an individual inherits two copies of a recessive allele, one from each parent.

Front

What is the difference between dominant and recessive traits?

Back

Dominant traits require only one copy of the allele to be expressed, while recessive traits require two copies.