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. It shows all possible combinations of alleles.

Front

What does homozygous mean?

Back

Homozygous refers to having two identical alleles for a particular gene, either dominant or recessive.

Front

What does heterozygous mean?

Back

Heterozygous refers to having two different alleles for a particular gene, one dominant and one recessive.

Front

What is the probability of an offspring having a specific genotype in a Punnett Square?

Back

Each box in a Punnett Square represents the probability of an offspring's genotype, typically expressed as a percentage.

Front

If a heterozygous long-tusked elephant is crossed with a homozygous recessive short-tusked elephant, what is the probability of the offspring having short tusks?

Back

50%.

Front

What is the probability of heterozygous offspring from a cross between a heterozygous and a homozygous recessive parent?

Back

50%.

Front

What does it mean if an allele is recessive?

Back

A recessive allele is one that is masked by a dominant allele and only expresses its trait when two copies are present.

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.

Front

In a genetic cross, what does a 25% probability indicate?

Back

A 25% probability indicates that there is a one in four chance of the offspring having a specific genotype.

Front

If Jabba the Hutt is heterozygous for a recessive syndrome and his mate is homozygous dominant, should he be worried about their children having the syndrome?

Back

No, because all offspring will inherit at least one dominant allele, preventing the syndrome.