Fertilization and life cycles Transitional Reasoning Download PDF

Questions

1. 1.

   A biologist analyzes the sexual life cycles of two distinct eukaryotic organisms to determine when meiosis and mitosis occur during their development. Organism 1 forms a multicellular diploid body that produces haploid gametes directly by meiosis, whereas Organism 2 forms a single-celled diploid zygote that immediately undergoes meiosis to generate haploid cells that develop into a multicellular body by mitosis. Based on these observations, which statement correctly evaluates the life cycles of these two organisms?

   • A) Organism 1 relies on fertilization to produce haploid spores, whereas Organism 2 relies on meiosis to produce diploid gametes.
   • B) Organism 1 exhibits a diploid-dominant life cycle where mitosis occurs in the diploid phase, whereas Organism 2 exhibits a haploid-dominant life cycle where mitosis occurs in the haploid phase.
   • C) Both organisms undergo alternation of generations because multicellular structures develop from both haploid and diploid phases in each species.
   • D) Organism 2 doubles its chromosome number during meiosis, eliminating the requirement for fertilization in its reproductive cycle.