Punnett Squares

Front

What is a Punnett Square?

Back

A Punnett Square is a diagram used to predict the genetic makeup of offspring from a cross between two parents.

Front

What does homozygous mean?

Back

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

Front

What does heterozygous mean?

Back

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

Front

What is the probability of producing a homozygous recessive offspring from a Tt x Tt cross?

Back

25%.

Front

What is the probability of producing a homozygous dominant offspring from a Tt x Tt cross?

Back

25%.

Front

In genetics, what does the term 'dominant' mean?

Back

Dominant refers to an allele that expresses its trait even when only one copy is present.

Front

In genetics, what does the term 'recessive' mean?

Back

Recessive refers to an allele that only expresses its trait when two copies are present.

Front

If tall (T) is dominant to short (t), what is the phenotype of a Tt plant?

Back

The phenotype of a Tt plant is tall.

Front

What is the expected phenotypic ratio from a Tt x Tt cross?

Back

The expected phenotypic ratio is 3 tall : 1 short.

Front

What is the expected genotypic ratio from a Tt x Tt cross?

Back

The expected genotypic ratio is 1 TT : 2 Tt : 1 tt.