Incomplete Dominance vs. Codominance exam Flashcards
Terms in this set (27)
Incomplete Dominance
A pattern of inheritance where heterozygous individuals show a blended phenotype that is an intermediate of the phenotypes from the two alleles.
Codominance
A pattern of inheritance where heterozygotes with two different alleles equally express both phenotypes from each allele in patches.
What phenotype results from a cross between a homozygous red flower and a homozygous white flower in incomplete dominance?
Pink flowers.
What does the term 'co' in codominance signify?
Together.
What is the phenotype of a heterozygous individual in codominance?
Both phenotypes are equally expressed in patches.
Example of Incomplete Dominance
Pink flowers from a cross between red and white flowers.
Example of Codominance
AB blood type in humans.
What are the possible alleles for human blood type?
IA, IB, and i.
What blood type results from the genotype IAIB?
AB blood type.
What does the genotype ii result in?
Type O blood.
What is the phenotype of a genotype IAi?
Type A blood.
What is the phenotype of a genotype IBi?
Type B blood.
What does the IA allele code for?
A molecules on the surface of red blood cells.
What does the IB allele code for?
B molecules on the surface of red blood cells.
What is the result of a cross between a homozygous red flower and a homozygous white flower in codominance?
Flowers with patches of red and white.
What is the key difference between incomplete dominance and codominance?
Incomplete dominance results in a blended phenotype, while codominance results in both phenotypes being equally expressed.
What does the lowercase i allele represent in human blood types?
A recessive allele that does not produce any surface molecules on red blood cells.
What is the phenotype of a genotype IAIA?
Type A blood.
What is the phenotype of a genotype IBIB?
Type B blood.
What does it mean if an allele is recessive?
It is masked by the presence of a dominant allele and does not affect the phenotype in a heterozygous individual.
What is the phenotype of a flower with genotype R1R2 in incomplete dominance?
Pink flower.
What is the phenotype of a flower with genotype R1R2 in codominance?
Flower with patches of red and white.
What does the term 'phenotype' refer to?
The observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.
What does the term 'genotype' refer to?
The genetic constitution of an organism in terms of its alleles.
What is the result of a cross between two heterozygous individuals in incomplete dominance?
A mix of red, white, and pink flowers.
What is the result of a cross between two heterozygous individuals in codominance?
A mix of flowers with patches of red and white.
What is the significance of understanding incomplete dominance and codominance?
It is crucial for grasping genetic variation and inheritance patterns, foundational in genetics and biology.