Punnett Squares

Front

What is a Punnett Square?

Back

A Punnett Square is a diagram used to predict the outcome of a genetic cross by showing the possible combinations of alleles from the parents.

Front

What does homozygous mean?

Back

Homozygous refers to having two identical alleles for a particular gene, such as AA or aa.

Front

What does heterozygous mean?

Back

Heterozygous refers to having two different alleles for a particular gene, such as Aa.

Front

What is the genotype for a homozygous dominant trait?

Back

The genotype for a homozygous dominant trait is represented as AA.

Front

What is the genotype for a homozygous recessive trait?

Back

The genotype for a homozygous recessive trait is represented as aa.

Front

What does it mean for an allele to be dominant?

Back

A dominant allele is one that expresses its trait even when only one copy is present (e.g., AA or Aa).

Front

What does it mean for an allele to be recessive?

Back

A recessive allele only expresses its trait when two copies are present (e.g., aa).

Front

In a Punnett Square, what are the possible genotypes from a cross of TT and tt?

Back

The possible genotypes are TT (25%), Tt (50%), and tt (25%).

Front

If T represents tall and t represents short, what is the phenotype of TT?

Back

The phenotype of TT is tall.

Front

What is the phenotype of Tt?

Back

The phenotype of Tt is also tall, since T is dominant.