Independent assortment Original Scenario-Based Practice

Questions

1. 1.

   On the crystalline moon of Thalassa, exobiologists study the celestial lantern-beetle, an organism possessing two unlinked autosomal genes that govern shell bioluminescence ($B/b$) and antenna geometry ($A/a$). When analyzing the gametes produced by a dihybrid individual with the genotype $AaBb$, researchers find four distinct allele combinations—$AB$, $Ab$, $aB$, and $ab$—formed in equal frequencies. Which cellular event during meiosis directly accounts for generating these four gamete classes in equivalent proportions?

   • A) The reciprocal crossing over between non-sister chromatids of a single homologous pair during prophase I
   • B) The semi-conservative replication of individual chromatids during premeiotic interphase S phase
   • C) The random alignment and independent segregation of non-homologous chromosome pairs across the metaphase I plate
   • D) The separation of identical sister chromatids toward opposite poles during anaphase II

Answers and step-by-step solutions appear after you finish the test.