Biology 9.2-9.3: Codominance and Incomplete Dominance

Front

What is incomplete dominance?

Back

A genetic situation in which one allele does not completely dominate another allele, resulting in a new phenotype that is a blend of the two traits.

Front

What is codominance?

Back

A genetic situation where both alleles in a heterozygote are fully expressed, resulting in offspring with a phenotype that is neither dominant nor recessive.

Front

What color flowers do Rr snapdragons produce?

Back

Pink, due to incomplete dominance between red (RR) and white (rr) traits.

Front

In a cross between a red radish (RR) and a white radish (rr), what is the phenotype of the offspring?

Back

All offspring will be purple (Rr) due to complete dominance.

Front

What percentage of offspring will be calico in a cross of black and tan cats?

Back

50%, due to codominance.

Front

If a Punnett square shows a 1:2:1 ratio, what does this indicate about the inheritance pattern?

Back

It indicates incomplete dominance, where one allele is not completely dominant over the other.

Front

What are the possible phenotypes of offspring from a cross of two heterozygous snapdragons (Rr x Rr)?

Back

1 Red (RR), 2 Pink (Rr), 1 White (rr).

Front

In incomplete dominance, what color will the offspring be if one parent is black and the other is white?

Back

Gray, as a blend of the two colors.

Front

What is the expected phenotypic ratio for a monohybrid cross involving codominance?

Back

1:2:1 ratio of the three phenotypes.

Front

What does a Punnett square represent in genetics?

Back

A diagram that predicts the genotypes of offspring from a genetic cross.