Codominance & Incomplete Dominance

Front

What is codominance?

Back

Codominance is a genetic scenario where both alleles in a heterozygous organism are fully expressed, resulting in offspring with a phenotype that is neither dominant nor recessive. Example: A calico cat with both orange and black fur.

Front

What is incomplete dominance?

Back

Incomplete dominance is a genetic scenario where the phenotype of a heterozygote is intermediate between the phenotypes of the two homozygotes. Example: A red flower crossed with a white flower produces pink flowers.

Front

What does homozygous dominant mean?

Back

Homozygous dominant refers to an organism that has two identical dominant alleles for a trait (e.g., YY).

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What does homozygous recessive mean?

Back

Homozygous recessive refers to an organism that has two identical recessive alleles for a trait (e.g., yy).

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What is a phenotype?

Back

A phenotype is the observable physical or biochemical characteristics of an organism, determined by both genetic makeup and environmental influences.

Front

What is a genotype?

Back

A genotype is the genetic constitution of an individual, represented by the alleles inherited from the parents.

Front

If a brown-haired (A) cat is crossed with a blond-haired (a) cat, what are the possible genotypes of the offspring?

Back

The possible genotypes are Aa (brown) and aa (blond).

Front

What is the expected phenotype ratio of offspring from a cross between a homozygous dominant and a homozygous recessive organism?

Back

All offspring will display the dominant phenotype.

Front

What is the expected phenotype ratio of offspring from a cross between two heterozygous organisms?

Back

The expected phenotype ratio is 3:1 (dominant:recessive).

Front

What is the significance of the Punnett square in genetics?

Back

A Punnett square is a diagram used to predict the genotypes and phenotypes of offspring from a genetic cross.