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 genotype mean?

Back

Genotype refers to the genetic makeup of an organism, specifically the alleles it possesses for a particular trait.

Front

What is the difference between dominant and recessive alleles?

Back

Dominant alleles are expressed in the phenotype even if only one copy is present, while recessive alleles are only expressed if two copies are present.

Front

What is the probability of producing a tall plant from a Tt x Tt cross?

Back

75% chance of producing a tall plant.

Front

What does heterozygous mean?

Back

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

Front

What does homozygous mean?

Back

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

Front

In a Punnett Square, what do the letters represent?

Back

The letters represent the alleles contributed by each parent.

Front

What is the phenotype of an organism?

Back

The phenotype is the observable physical or biochemical characteristics of an organism, determined by its genotype.

Front

If a plant has the genotype Rr, what color flowers will it have?

Back

It will have red flowers, since red (R) is dominant over white (r).

Front

What is the expected ratio of genotypes from a monohybrid cross?

Back

The expected ratio is 1:2:1 for homozygous dominant, heterozygous, and homozygous recessive.