Punnett Square Genetics

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 term 'phenotype' refer to?

Back

Phenotype refers to the physical traits or characteristics of an organism, such as height, color, and shape.

Front

What is 'genotype'?

Back

Genotype is the genetic makeup of an organism, represented by the alleles it possesses (e.g., TT, Tt, tt).

Front

What is the difference between homozygous and heterozygous alleles?

Back

Homozygous alleles are identical (e.g., BB or tt), while heterozygous alleles are different (e.g., Tt).

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What is incomplete dominance?

Back

Incomplete dominance is a type of inheritance where the phenotype of the offspring is a blend of the parents' phenotypes (e.g., red and white flowers producing pink flowers).

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What is co-dominance?

Back

Co-dominance is a type of inheritance where both alleles in a heterozygous organism are fully expressed, resulting in a phenotype that shows both traits (e.g., checkered chickens from black and white parents).

Front

How do you perform a Punnett Square?

Back

To perform a Punnett Square, list the alleles of one parent across the top and the alleles of the other parent down the side, then fill in the squares to show the possible genotypes of the offspring.

Front

What is the expected genotype ratio from a cross between Tt and tt?

Back

The expected genotype ratio is 1 Tt : 1 tt.

Front

What is the expected phenotype ratio from a cross between Tt and tt?

Back

The expected phenotype ratio is 1 tall : 1 short.

Front

What does it mean for an organism to be homozygous recessive?

Back

An organism is homozygous recessive if it has two recessive alleles for a trait (e.g., tt for short plants).