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 'dominant' mean in genetics?

Back

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

Front

What does 'recessive' mean in genetics?

Back

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

Front

What is the genotype of an organism?

Back

The genotype is the genetic makeup of an organism, represented by the alleles it possesses.

Front

What is a phenotype?

Back

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

Front

If a red flower (Rr) is crossed with a white flower (rr), what are the possible genotypes of the offspring?

Back

The possible genotypes are 0 RR; 2 Rr: 2 rr.

Front

What is the phenotype of the offspring from a cross of A-Brown hair (dominant) and a-blond hair (recessive)?

Back

The phenotype of the offspring is 75% Brown Hair and 25% Blond Hair.

Front

What does heterozygous mean?

Back

Heterozygous refers to having two different alleles for a particular gene, such as Aa.

Front

What does homozygous mean?

Back

Homozygous refers to having two identical alleles for a particular gene, such as AA or aa.

Front

In a Punnett Square, what do the letters represent?

Back

The letters represent the alleles contributed by each parent.