Understanding Incomplete Dominance

The video tutorial explores Mendelian genetics, focusing on the rule of dominance where dominant alleles determine traits unless two recessive alleles are present. It then introduces incomplete dominance, where neither allele is completely dominant, resulting in a blend of traits in heterozygous combinations. An example with flower colors illustrates this concept, showing how a cross between red and white flowers results in pink flowers. The use of Punnett squares to predict these outcomes is also discussed, emphasizing the blend of phenotypes in incomplete dominance.

What is the primary rule of dominance in Mendelian genetics?

• Recessive alleles always determine the trait.

• Alleles do not affect the traits.

• Dominant alleles always determine the trait unless two recessive alleles are present.

• Traits are determined by a blend of alleles.

In incomplete dominance, what happens when a heterozygous combination occurs?

• A blend of both traits is expressed.

• The recessive trait is fully expressed.

• The dominant trait is fully expressed.

• Neither trait is expressed.

What color flowers result from crossing a homozygous dominant red flower with a homozygous recessive white flower in incomplete dominance?

• Red

• White

• Pink

• Blue

In the context of incomplete dominance, what does a heterozygous combination typically result in?

• No phenotype

• A blend of the two phenotypes

• A dominant phenotype

• A recessive phenotype

Which of the following is NOT true about incomplete dominance?

• It results in a blend of traits.

• Neither allele is completely dominant.

• It follows the rule of dominance.

• Heterozygous combinations show a new phenotype.

What is the phenotype of a flower with a heterozygous combination in incomplete dominance?

• Pink

• White

• Red

• Yellow

How does incomplete dominance differ from Mendelian dominance?

• Incomplete dominance results in a blend of traits, while Mendelian dominance does not.

• Incomplete dominance follows the rule of dominance strictly.

• Mendelian dominance results in a blend of traits.

• Incomplete dominance does not involve alleles.