Unit 6, Lesson 2: Codominance

Front

What is codominance?

Back

Codominance is a genetic scenario where both alleles in a heterozygous individual are fully expressed, resulting in a phenotype that is neither dominant nor recessive.

Front

Give an example of codominance in plants.

Back

In some flowers, red (RR) and blue (BB) alleles can produce speckled flowers (RB) when crossed.

Front

What is the phenotypic ratio when a red flower (RR) is crossed with a speckled flower (RB)?

Back

The phenotypic ratio is 2 red flowers to 2 speckled flowers.

Front

What is the genotype for a roan-colored cattle?

Back

The genotype for roan color in cattle is RW, where R represents red and W represents white.

Front

What is the difference between codominance and incomplete dominance?

Back

In codominance, both alleles are fully expressed, while in incomplete dominance, the phenotype is a blend of the two alleles.

Front

What is an example of codominance in animals?

Back

Calico cats exhibit codominance, showing both orange and black fur due to the presence of both alleles.

Front

What does it mean if an allele is dominant?

Back

A dominant allele is one that expresses its trait even when only one copy is present in a heterozygous individual.

Front

What does it mean if an allele is recessive?

Back

A recessive allele only expresses its trait when two copies are present in a homozygous individual.

Front

How can you identify codominance in a genetic cross?

Back

Codominance can be identified when both traits appear simultaneously in the offspring, such as in speckled flowers.

Front

What is the expected outcome of a cross between two heterozygous codominant individuals?

Back

The expected outcome would typically show a 1:2:1 ratio of the three phenotypes.