[Campbell Biology P.570] The text describes the speciation of Helianthus anomalus as a resul... | Practice Question

The text describes the speciation of Helianthus anomalus as a result of hybridization between H. annuus and H. petiolaris. How does this specific case of speciation differ from allopolyploid speciation according to the provided information?

  • A: Helianthus anomalus speciation involves a change in chromosome number, while allopolyploid speciation does not.
  • B: In Helianthus anomalus speciation, the hybrid maintains the same chromosome number as its parents (2n=34), whereas allopolyploid speciation involves a change in chromosome number.
  • C: Helianthus anomalus speciation always leads to sterile hybrids, unlike allopolyploid speciation, which restores fertility.
  • D: Allopolyploid speciation is typically rapid, whereas Helianthus anomalus speciation is a gradual process over millions of years.

Explanation

The text explicitly differentiates the speciation of Helianthus anomalus from allopolyploid speciation by noting that in the former, the hybrid maintains the same chromosome number 2n=34 as its parents, whereas allopolyploid speciation involves a change in chromosome number, typically a doubling.