Final answer:
The type of cell division that requires two sequential rounds of division in sexually reproducing organisms is meiosis.
Step-by-step explanation:
In sexually reproducing organisms, the type of cell division that requires two sequential rounds of division is meiosis. Meiosis is a type of cell division that occurs in sexually reproducing organisms to generate haploid cells. It consists of two rounds of division, referred to as meiosis I and meiosis II. During meiosis I, homologous chromosomes pair up and exchange genetic material, resulting in genetic recombination. Then, the homologous chromosomes separate into two daughter cells. In meiosis II, the sister chromatids of each chromosome separate, resulting in four haploid daughter cells.