Dihybrid crosses

Front

What is a dihybrid cross?

Back

A genetic cross that involves two traits, each represented by two alleles.

Front

What does the term 'homozygous' mean?

Back

An organism with two identical alleles for a trait (e.g., RR or rr).

Front

What does the term 'heterozygous' mean?

Back

An organism with two different alleles for a trait (e.g., Rr).

Front

What is the phenotypic ratio expected from a dihybrid cross?

Back

The expected phenotypic ratio is 9:3:3:1.

Front

What is a genotype?

Back

The genetic makeup of an organism, represented by alleles (e.g., Rr, YY).

Front

What are gametes?

Back

Reproductive cells (sperm and eggs) that carry one allele for each gene.

Front

How do you determine the possible gametes from a genotype?

Back

Use the FOIL method (First, Outside, Inside, Last) for two traits.

Front

What is the significance of a Punnett square?

Back

A tool used to predict the genotypes and phenotypes of offspring from genetic crosses.

Front

What does 'dominant' mean in genetics?

Back

An allele that expresses its trait even in the presence of a recessive allele.

Front

What does 'recessive' mean in genetics?

Back

An allele that only expresses its trait when two copies are present.