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 the letter 'W' represent in genetics?

Back

In this context, 'W' represents the allele for white hair.

Front

What does the letter 'w' represent in genetics?

Back

In this context, 'w' represents the allele for non-white hair.

Front

If a horse with genotype WW is crossed with a horse with genotype ww, what fraction of the offspring will have white hair?

Back

All (100%) of the offspring will have white hair.

Front

In a heterozygous genotype, which allele is expressed in the phenotype?

Back

The dominant allele is expressed in the phenotype.

Front

How many alleles does each person carry for a trait?

Back

Each person carries 2 alleles for a trait.

Front

What is the ratio of homozygous recessive offspring from a cross of two heterozygous parents?

Back

1 in 4 (or 25%) of the offspring will be homozygous recessive.

Front

What is a homozygous genotype?

Back

A homozygous genotype has two identical alleles for a trait, such as AA or aa.

Front

What is a heterozygous genotype?

Back

A heterozygous genotype has two different alleles for a trait, such as Aa.

Front

What does 'dominant' mean in genetics?

Back

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