Independent assortment Original Scenario-Based Download PDF

Questions

1. 1.

   In the bioluminescent nebula moth, the gene governing wing glow color (alleles L and l) and the gene regulating antennal shape (alleles P and p) are located on separate, non-homologous autosomes. A researcher tracks meiotic division in a captive male moth possessing the dihybrid genotype LlPp. Which statement correctly predicts how independent assortment determines the allele combinations in the resulting mature gametes?

   • A) Crossing over between non-sister chromatids during prophase II ensures that the dominant alleles remain grouped together in a three-to-one ratio relative to recessive alleles.
   • B) Random alignment of non-homologous chromosome pairs along the metaphase I plate yields four genetically distinct gametes—LP, Lp, lP, and lp—in roughly equal proportions.
   • C) Maternal homologs always migrate toward the same cellular pole during anaphase I, restricting the viable sperm to purely parental combinations.
   • D) Complete physical linkage across centromeres forces the L and p alleles into identical daughter cells, preventing recombinant combinations from forming.