[Campbell Biology P.336] Why are lethal dominant alleles much less common than lethal recess... | Practice Question

Why are lethal dominant alleles much less common than lethal recessive alleles?

  • A: Lethal dominant alleles often cause the death of the afflicted individual before they can reproduce.
  • B: Lethal recessive alleles can be passed on by heterozygous carriers who have a normal phenotype.
  • C: Both A and B are correct.
  • D: Dominant alleles mutate into recessive alleles more frequently.

Explanation

The text explains both sides of the coin. A lethal dominant allele is unlikely to be passed on because it often kills the host before reproduction A . In contrast, a lethal recessive allele can be hidden in healthy heterozygous carriers, allowing it to be passed on to the next generation undetected B . Together, these two factors explain why lethal dominant alleles are much rarer.