Platyfish with Spots Have an X-Linked Gene That Produces the Spots.All

question 205

Multiple Choice

Platyfish with spots have an X-linked gene that produces the spots.All platyfish have an autosomal repressor that inhibits the expression of the spot-producing gene.The closely related swordtail lacks both the spot-producing gene and the repressor.In backcrosses between these two species, some hybrids receive the spot-producing gene, but not the repressor.These individuals can develop malignant tumors, because the expression of the spot-producing gene is not properly regulated.This appears to be an example of

• A) speciation via reinforcement.
• B) polymorphism.
• C) the Dobzhansky-Muller model of speciation.
• D) hybrids surviving just as well as nonhybrids.
• E) an inability to hybridize.

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