2 Factor Crosses, Incomplete Dominance, and Codominance

Front

What is codominance?

Back

Codominance is a genetic scenario where both alleles in a heterozygote are fully expressed, resulting in offspring with a phenotype that is neither dominant nor recessive. Example: AB blood type in humans.

Front

What is incomplete dominance?

Back

Incomplete dominance is a genetic situation where one allele does not completely dominate another, resulting in a phenotype that is a blend of the two. Example: Red and white flowers producing pink flowers.

Front

What is the genotype for a pea plant homozygous for round seeds (R) and heterozygous for yellow seeds?

Back

RRYy

Front

What is the phenotype of a plant with genotype Rr?

Back

The phenotype is round seeds, as R (round) is dominant over r (wrinkled).

Front

What type of inheritance pattern is shown when a tall plant (TT) is crossed with a short plant (ss) resulting in medium height plants (Ts)?

Back

Incomplete Dominance

Front

What is the difference between codominance and incomplete dominance?

Back

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

Front

What is a dihybrid cross?

Back

A dihybrid cross is a genetic cross that examines the inheritance of two different traits, each represented by two alleles.

Front

What is the expected phenotypic ratio in a dihybrid cross?

Back

The expected phenotypic ratio in a dihybrid cross is 9:3:3:1.

Front

What does the term 'allele' mean?

Back

An allele is a variant form of a gene that can produce different traits.

Front

What is the significance of the Punnett square in genetics?

Back

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