Pedigrees

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 for an individual to be a carrier of a trait?

Back

A carrier is an individual who has one copy of a recessive allele that does not manifest in their phenotype but can be passed on to offspring.

Front

What is the difference between dominant and recessive alleles?

Back

Dominant alleles express their trait even if only one copy is present, while recessive alleles require two copies to express the trait.

Front

How can you identify a recessive trait in a pedigree?

Back

A recessive trait typically appears in individuals who have two recessive alleles, and it may skip generations, appearing in offspring of carrier parents.

Front

What does a horizontal line connecting a square and a circle represent in a pedigree?

Back

A horizontal line connecting a square (male) and a circle (female) represents a mating or union between the two individuals.

Front

What does a vertical line descending from a couple in a pedigree indicate?

Back

A vertical line descending from a couple indicates their offspring or children.

Front

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

Back

The number of generations in a pedigree can be determined by counting the horizontal rows of individuals from the oldest generation at the top to the youngest at the bottom.

Front

What is the significance of Roman numerals in a pedigree chart?

Back

Roman numerals are used to denote different generations in a pedigree chart, with each numeral representing a specific generation.

Front

What does the notation 'aa' signify in genetics?

Back

The notation 'aa' signifies a homozygous recessive genotype, meaning the individual has two copies of the recessive allele.

Front

What is the genotype of an individual with one dominant and one recessive allele?

Back

The genotype of an individual with one dominant and one recessive allele is heterozygous, typically represented as 'Aa'.