Rice plants may be tolerant or intolerant to flooding. A true-breeding tolerant plant was crossed with a true-breeding intolerant plant, creating an F₁generation. When plants from the F₁generation are crossed to each other, approximately 75% of the resultant F₂generation was tolerant to flooding. What does this most likely suggest about the flood-tolerant and flood-intolerant alleles? A) Multiple alleles control flood-tolerance. B) The alleles for flood-tolerance and flood-intolerance are codominant. C) The allele for flood-tolerance is incompletely dominant. D) The allele for flood-intolerance is dominant, while the allele for flood-tolerance is recessive. E) The allele for flood-tolerance is dominant, while the allele for flood-intolerance is recessive.

Question

Quizplus · Accepted Answer

Given that 75% of the offspring are tolerant to flooding when two heterozygous plants are crossed, this suggests a simple Mendelian inheritance pattern where the flood-tolerant trait is dominant. According to Mendel's laws, a cross between two heterozygous individuals (Tt x Tt, where T is the dominant tolerant allele and t is the recessive intolerant allele) would result in a 3:1 ratio of tolerant to intolerant offspring, which matches the observed outcome.

Rice Plants May Be Tolerant or Intolerant to Flooding