Notes: Incomplete Dominance, Codominance, & Sex-Linked Traits

Notes: Incomplete Dominance, Codominance, & Sex-Linked Traits

What is incomplete dominance? ______

______

Example problem: In snapdragons, red color (R) is incompletely dominant over white color (W). A plant with red flowers is crossed with a plant with white flowers. Cross: ______X ______

What are the possible phenotypes with ratios for the offspring flowers? ______

What are the possible genotypes with ratios for the offspring flowers? ______

What is codominance? ______

______

Example: In chickens the alleles for black (B) and white (W) feathers are codominant. Heterozygous chickens are speckled. A black-feathered hen is crossed with a white-feathered rooster. Cross: ______X ______

What are the possible phenotypes with ratios for the offspring chickens? ______

What are the possible genotypes with ratios for the offspring chickens? ______

What are multiple allele traits? ______

______

Example: In humans, there are multiple blood-type alleles. Types A and B are codominant. Type O is recessive to both Type A and Type B. What are the phenotypes for each of the following blood-type genotypes?

AA ______BB ______AB ______

AO ______BO ______OO ______

What are sex-linked traits? ______

______

Example: In fruit flies, white eyes (r) are recessive to red eyes (R) on the X-chromosome. A heterozygous red-eyed female fruit fly is crossed with a red-eyed male fruit fly. Cross: ______X ______

What are the possible phenotypes with ratios for the offspring fruit flies?

What are the possible genotypes with ratios for the offspring fruit flies?

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