[Campbell Biology P.336] Huntington's disease is caused by a lethal dominant allele, yet it ... | Practice Question

Huntington's disease is caused by a lethal dominant allele, yet it persists in the human population. What feature of the disease allows it to be passed on to future generations?

  • A: The disease is relatively harmless.
  • B: The symptoms appear after reproductive age.
  • C: It is a multifactorial disorder, not purely genetic.
  • D: The allele provides a selective advantage against other diseases.

Explanation

The text states that a lethal dominant allele can be passed on if the 'lethal disease symptoms first appear after reproductive age.' For Huntington's, it specifies this age is about 35 to 45. This late onset means an individual can have children before they are aware they carry the fatal allele.