Genetics & Punnett Squares

Front

What is a genotype?

Back

The genetic makeup of an organism, represented by letters (e.g., WW, Ww, ww).

Front

What is a phenotype?

Back

The observable physical characteristics of an organism, determined by its genotype.

Front

What does homozygous mean?

Back

An organism with two identical alleles for a trait (e.g., WW or ww).

Front

What does heterozygous mean?

Back

An organism with two different alleles for a trait (e.g., Ww).

Front

What is a dominant trait?

Back

A trait that is expressed in the phenotype even when only one allele is present.

Front

What is a recessive trait?

Back

A trait that is only expressed in the phenotype when two recessive alleles are present.

Front

What is a Punnett square?

Back

A diagram used to predict the outcome of a genetic cross by showing the possible combinations of alleles.

Front

If a plant has the genotype Gg, what is its phenotype?

Back

Green, because G (green) is dominant over g (yellow).

Front

In a test cross, what is being determined?

Back

The genotype of an organism with a dominant phenotype by crossing it with a homozygous recessive organism.

Front

What is the expected phenotypic ratio in a monohybrid cross of two heterozygous parents?

Back

3:1, where 3 show the dominant trait and 1 shows the recessive trait.