Genetics: 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 trait' mean?

Back

A dominant trait is a genetic trait that is expressed in the phenotype even when only one copy of the allele is present.

Front

What does 'recessive trait' mean?

Back

A recessive trait is a genetic trait that is only expressed in the phenotype when two copies of the allele are present.

Front

What is the probability of an offspring showing a dominant trait if both parents are heterozygous?

Back

75%.

Front

What is the probability of an offspring showing a recessive trait if both parents are heterozygous?

Back

25%.

Front

What does 'homozygous' mean?

Back

Homozygous refers to having two identical alleles for a particular gene (e.g., BB or bb).

Front

What does 'heterozygous' mean?

Back

Heterozygous refers to having two different alleles for a particular gene (e.g., Bb).

Front

If one parent is homozygous dominant (BB) and the other is homozygous recessive (bb), what is the probability of offspring being heterozygous?

Back

100%.

Front

What is an allele?

Back

An allele is a variant form of a gene that can produce different traits.

Front

What is the genotype of an organism?

Back

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