Punnet Squares Practice

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 it mean for an allele to be 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 for an allele to be recessive?

Back

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

Front

If brown eyes (B) are dominant over blue eyes (b), what are the possible genotypes for brown eyes?

Back

The possible genotypes for brown eyes are BB (homozygous dominant) and Bb (heterozygous).

Front

What is the genotype of a homozygous recessive individual for eye color?

Back

The genotype of a homozygous recessive individual for eye color is bb.

Front

In a cross between two heterozygous brown-eyed parents (Bb x Bb), what is the expected phenotypic ratio of their offspring?

Back

The expected phenotypic ratio is 3 brown-eyed (B_) to 1 blue-eyed (bb).

Front

What is the probability of a child having blue eyes if both parents are heterozygous (Bb)?

Back

The probability is 25%.

Front

If a heterozygous brown-eyed male (Bb) marries a homozygous recessive female (bb), what is the chance of having a brown-eyed child?

Back

The chance is 50%.

Front

What are the genotypes of two heterozygous parents?

Back

The genotypes are both Aa.

Front

If a homozygous dominant female (BB) has a child with a heterozygous male (Bb), what is the chance of the child having blue eyes?

Back

The chance is 0%.