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 do the letters G and g represent in genetics?

Back

G represents a dominant allele (green scales) and g represents a recessive allele (white scales).

Front

What is the expected offspring ratio when crossing two heterozygous parents (Gg x Gg)?

Back

The expected offspring ratio is 3 green scales to 1 white scale.

Front

What is a genotype?

Back

A genotype is the genetic makeup of an organism, represented by the alleles it possesses (e.g., Aa, Bb).

Front

What is a phenotype?

Back

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

Front

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

Back

The probability is 25%.

Front

What does it mean if two organisms have the same phenotype but different genotypes?

Back

It means they exhibit the same physical traits but have different genetic compositions (e.g., one is homozygous BB and the other is heterozygous Bb).

Front

What is the expected offspring ratio when crossing a heterozygous parent (Dd) with a homozygous recessive parent (dd)?

Back

The expected offspring ratio is 50% with dimples (D) and 50% without dimples (d).

Front

What is the difference between dominant and recessive alleles?

Back

A dominant allele is expressed in the phenotype even if only one copy is present, while a recessive allele is only expressed if two copies are present.

Front

What does the term homozygous mean?

Back

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