Punnett Squares

Front

What is a Punnett Square?

Back

A chart that shows all the possible combinations of alleles that can result from a genetic cross.

Front

What genotype represents a purebred dominant trait?

Back

PP

Front

What is a dominant allele?

Back

This trait always shows up in an organism when the allele is present.

Front

What is a recessive allele?

Back

This trait only shows up in an organism when two copies of the allele are present.

Front

What does homozygous mean?

Back

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

Front

What does heterozygous mean?

Back

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

Front

What is the genotype for homozygous recessive?

Back

rr

Front

What is codominance?

Back

A situation in which both alleles in a heterozygous genotype are fully expressed.

Front

What is the purpose of a Punnett Square?

Back

To predict the probability of offspring inheriting particular traits.

Front

If a parent has the genotype Aa, what alleles can they pass on to their offspring?

Back

A or a.