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 heterozygous mean?

Back

Heterozygous refers to having two different alleles for a specific gene, such as Bb.

Front

What does homozygous mean?

Back

Homozygous refers to having two identical alleles for a specific gene, such as BB or bb.

Front

What is the definition of genotype?

Back

Genotype is the genetic constitution of an individual, represented by the alleles (e.g., Aa, BB).

Front

What is the definition of phenotype?

Back

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

Front

What is the probability of an offspring having brown eyes if one parent is BB and the other is Bb?

Back

100% chance of having brown eyes.

Front

What is the probability of an offspring having blue eyes if one parent is Bb and the other is Bb?

Back

25% chance of having blue eyes.

Front

In a Punnett Square, what does each box represent?

Back

Each box represents the probability of a specific genotype occurring in the offspring.

Front

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

Back

1 in 4 will be homozygous recessive (tt).

Front

What is the definition of dominant trait?

Back

A dominant trait is one that is expressed in the phenotype even when only one allele is present.