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 a dominant allele?

Back

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

Front

What is a recessive allele?

Back

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

Front

In a Punnett Square, where are the parent alleles written?

Back

The parent alleles are written outside of the boxes, typically on the top and left side.

Front

What is the phenotype of a plant with genotype GG?

Back

The phenotype is green, as GG represents a homozygous dominant trait.

Front

What is the expected phenotype ratio when two heterozygous plants (Aa) are crossed?

Back

The expected phenotype ratio is 75% dominant (e.g., red) and 25% recessive (e.g., white).

Front

What does it mean if a trait is expressed 100% of the time in a cross?

Back

It means that all offspring will show that trait, indicating that the trait is dominant.

Front

What is the genotype of a homozygous recessive organism?

Back

The genotype of a homozygous recessive organism is represented as 'aa'.