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 over several generations.

Front

What does phenotype mean?

Back

Phenotype refers to the observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.

Front

What is a genotype?

Back

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

Front

What does it mean if a trait is recessive?

Back

A recessive trait is one that is expressed in the phenotype only when two copies of the recessive allele are present.

Front

What does a filled circle represent in a pedigree?

Back

A filled circle represents an affected female.

Front

What does a filled square represent in a pedigree?

Back

A filled square represents an affected male.

Front

What do half-colored symbols represent in a pedigree?

Back

Half-colored symbols represent individuals who are carriers (heterozygous) for a trait.

Front

How can you determine the number of generations in a pedigree?

Back

Count the horizontal rows of symbols; each row represents a generation.

Front

What is the significance of the letters 'GG', 'Gg', and 'gg' in genetics?

Back

'GG' represents a homozygous dominant genotype, 'Gg' represents a heterozygous genotype, and 'gg' represents a homozygous recessive genotype.

Front

What is the purpose of using pedigrees in genetics?

Back

Pedigrees are used to track the inheritance of traits and diseases through generations, helping to identify carriers and affected individuals.