Punnett Square, Incomplete & Codominance Review

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 two parents.

Front

What are alleles?

Back

Alleles are different forms of a gene that can exist at a specific locus on a chromosome.

Front

What does it mean if an allele is dominant?

Back

A dominant allele is one that expresses its trait even when only one copy is present in the genotype.

Front

What does it mean if an allele is recessive?

Back

A recessive allele only expresses its trait when two copies are present in the genotype.

Front

What is codominance?

Back

Codominance is a genetic scenario where both alleles in a heterozygote are fully expressed, resulting in a phenotype that shows both traits.

Front

What is incomplete dominance?

Back

Incomplete dominance is a genetic scenario where the phenotype of a heterozygote is intermediate between the phenotypes of the two homozygotes.

Front

If B = brown fur and b = white fur, what is the genotype for a brown-furred animal that is homozygous?

Back

The genotype is BB.

Front

In a Punnett Square, what does each box represent?

Back

Each box represents a possible genotype of the offspring resulting from the combination of alleles from the parents.

Front

What is the probability of getting a recessive phenotype from a Bb x Bb cross?

Back

The probability is 25%.

Front

What is the phenotype ratio for a monohybrid cross between two heterozygous parents?

Back

The phenotype ratio is 3:1.