Genetics: Incomplete Dominance vs Codominance

Explain the difference between incomplete dominance and codominance.

What is the genotype for black chickens?

What is the genotype for white chickens?

What is the genotype for erminette chickens?

What is the probability of having a black chick if two erminette chickens are crossed?

What is the probability of having a white chick if two erminette chickens are crossed?

What is the probability that a black chicken and a white chicken will have erminette chicks?

What is the phenotype of a plant with the genotype RR?

What is the phenotype of a plant with the genotype WW?

What is the phenotype of a plant with the genotype RW?

What is the probability of producing a pink-flowered plant when a pink-flowered plant is crossed with a white-flowered plant?

What cross will produce the most pink-flowered plants?

Sex chromosomes determine an organism's _____

All other chromosomes, which do not directly affect an organism's sex, are called _____

Sex-linked genes are located on the _____

Incomplete Dominance vs. Codominance

Incomplete dominance occurs when the phenotype is a blend of the two parental phenotypes.
Codominance results in both parental phenotypes being fully expressed simultaneously.

Feather Color in Chickens

Black feather color is represented by the genotype BB.
White feather color is represented by the genotype WW.
Heterozygous genotype (BW) produces the erminette phenotype, exhibiting both black and white feathers.

Probability from Erminette Chickens

The probability of two erminette chickens producing a black chick is 25%.
The probability of producing a white chick from two erminette chickens is also 25%.

Black and White Chicken Cross

A black chicken crossed with a white chicken will result in 100% erminette chicks.

Flower Color in Snapdragons

In snapdragons, flower color is controlled by incomplete dominance with alleles red (R) and white (W).
The genotype RR results in a red flower phenotype.
The genotype WW results in a white flower phenotype.
The heterozygous genotype RW gives a pink flower phenotype.

Probability of Pink-Flowered Snapdragons

When a pink-flowered (RW) plant is crossed with a white-flowered (WW) plant, there is a 50% chance of producing another pink-flowered plant.

Best Cross for Pink-Flowered Plants

To produce the most pink-flowered plants, cross a red-flowered plant (RR) with a white-flowered plant (WW).

Sex Chromosomes

Sex chromosomes are responsible for determining an organism's sex.

Autosomes

Autosomes are all chromosomes that do not influence an organism's sex.

Sex-Linked Genes

Sex-linked genes are found on sex chromosomes, influencing traits related to the organism's sex.

This quiz focuses on the concepts of incomplete dominance and codominance in genetics, providing explanations and examples. Discover how these genetic phenomena influence phenotypes in organisms, especially through the example of chicken feather color. Test your knowledge and understanding of these important genetic principles.