11.3 Flashcards
Are all alleles dominant or recessive?
Some are neither.
What is incomplete dominance?
One allele is not completely dominant in the phenotype. The heterozygous phenotype is some where between the two homozygous phenotypes.
What is codominance?
Both alleles contribute to the phenotype equally.
What are multiple alleles?
More that two alleles exist for the same trait.
Individuals still only have two alleles, but there are more that two possible combinations in the populations.
What are polygenic traits?
Traits controlled by two or more genes. How skin color is determined.
Blood type A
iAi or iAiA
AA or OO
Can receive A or O
Blood type B
iBi or iBiB
BB or OO
Can receive B or O
Blood type AB
iAiB
AB
Can receive A, B, AB, or O
Blood type O
ii
OO
Can receive O
Are most traits controlled by only one gene?
No, the majority are controlled by more than one.
