The African Clawed Frog (Xenopus Laevis) Is Allotetraploid, Likely as a Result

question 48

Multiple Choice

The African clawed frog (Xenopus laevis) is allotetraploid, likely as a result of an interspecies mating long ago, followed by a duplication of the entire genome. Xenopus laevis is fertile and has a normal life cycle. In contrast, mules, the allodiploid offspring of a male donkey and a female horse, are generally sterile. Why can Xenopus reproduce and mules cannot?

• A) Frogs are less sensitive to multiple copies of the genome than mammals.
• B) In allotetraploid organisms each chromosome has a chromosome to pair up with in meiosis, whereas in allodiploid organisms they do not.
• C) The two frogs that interbred to form the Xenopus laevis must have been more closely genetically related than the donkey and horse are.
• D) The mule must have a genetic mutation that prevents it from reproducing.

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