Pedigrees & Dihybrid Crosses

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.

Front

What does it mean for a trait to be recessive?

Back

A recessive trait is one that requires two copies of the recessive allele for the trait to be expressed in the phenotype.

Front

What is the genotype of an individual with Cystic Fibrosis?

Back

The genotype is 'cc', as Cystic Fibrosis is a recessive trait.

Front

What does a half-colored symbol represent in a pedigree chart?

Back

A half-colored symbol indicates that the individual is a carrier (heterozygous) for a recessive trait.

Front

What are alleles?

Back

Alleles are different versions of a gene that can exist at a specific locus on a chromosome.

Front

What is a dihybrid cross?

Back

A dihybrid cross is a genetic cross that examines the inheritance of two different traits, each represented by two alleles.

Front

What is the purpose of a Punnett square?

Back

A Punnett square is used to predict the genotypes and phenotypes of offspring from a genetic cross.

Front

What does the term 'homozygous' mean?

Back

Homozygous refers to having two identical alleles for a particular gene (e.g., AA or aa).

Front

What does the term 'heterozygous' mean?

Back

Heterozygous refers to having two different alleles for a particular gene (e.g., Aa).

Front

How many gametes can be produced from a genotype of GgBb?

Back

Four gametes can be produced: GB, Gb, gB, gb.