Punnett Squares

Front

What is a Punnett Square?

Back

A Punnett Square is a diagram used to predict the genotypes of offspring from a genetic cross.

Front

How many alleles does a child inherit from each parent for each trait?

Back

1 allele from each parent.

Front

What does a genotype represent?

Back

A genotype represents the genetic makeup of an individual, specifically the alleles they possess.

Front

What is the phenotype?

Back

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

Front

What is the probability of obtaining a homozygous dominant offspring from a cross of two heterozygous parents (Bb x Bb)?

Back

25%.

Front

What does it mean for an organism to be homozygous?

Back

An organism is homozygous when it has two identical alleles for a particular trait.

Front

What does it mean for an organism to be heterozygous?

Back

An organism is heterozygous when it has two different alleles for a particular trait.

Front

What is the expected phenotypic ratio from a monohybrid cross of two heterozygous parents?

Back

3:1 ratio of dominant to recessive phenotypes.

Front

What is the expected genotypic ratio from a monohybrid cross of two heterozygous parents?

Back

1:2:1 ratio of homozygous dominant, heterozygous, and homozygous recessive genotypes.

Front

What is the significance of the boxes in a Punnett Square?

Back

Each box represents a possible genotype of the offspring and the probability of that genotype occurring.