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, used to analyze the inheritance of traits.

Front

What does it mean if a trait is recessive?

Back

A recessive trait is one that is not expressed in the presence of a dominant allele. An individual must have two copies of the recessive allele to express the trait.

Front

What is a genotype?

Back

A genotype is the genetic constitution of an individual, specifically the alleles present for a particular gene.

Front

What is a dominant trait?

Back

A dominant trait is one that is expressed in the phenotype even when only one copy of the allele is present.

Front

How many alleles does a person inherit from each parent for a trait?

Back

A person inherits one allele from each parent, resulting in two alleles for each trait.

Front

What is the difference between homozygous and heterozygous genotypes?

Back

Homozygous genotypes have two identical alleles for a trait (e.g., BB or bb), while heterozygous genotypes have two different alleles (e.g., Bb).

Front

What does it mean for an individual to be a carrier of a trait?

Back

A carrier is an individual who has one copy of a recessive allele and one copy of a dominant allele, meaning they do not express the trait but can pass the recessive allele to offspring.

Front

What is the significance of skipping generations in a pedigree?

Back

Skipping generations in a pedigree often indicates that the trait is recessive, as it may not be expressed in every generation.

Front

What is the phenotype?

Back

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

Front

What is the purpose of using pedigrees in genetics?

Back

Pedigrees are used to track the inheritance patterns of traits, identify carriers, and predict the likelihood of offspring inheriting certain traits.