Punnett Squares - Complete Dominance

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 homozygous mean?

Back

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

Front

What does heterozygous mean?

Back

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

Front

What is the genotype of a plant with smooth peas if smooth is dominant over wrinkled?

Back

The genotype could be either homozygous dominant (RR) or heterozygous (Rr).

Front

What is the phenotype of a plant with the genotype 'rr'?

Back

The phenotype would be wrinkled peas, as 'r' is the recessive allele.

Front

What is the probability of obtaining a homozygous recessive offspring from a cross between Rr and Rr?

Back

The probability is 25%.

Front

What is the universal donor blood type?

Back

The universal donor blood type is O.

Front

What does it mean if a trait is dominant?

Back

A dominant trait is one that will express itself in the phenotype even if only one dominant allele is present.

Front

What does it mean if a trait is recessive?

Back

A recessive trait will only express itself in the phenotype if two recessive alleles are present.

Front

In a Punnett Square, what do the letters represent?

Back

The letters represent the alleles contributed by each parent.