What marks the end of meiosis I?

• A. Two nuclei form and cytokinesis occurs
• B. Crossing over occurs
• C. DNA replication occurs
• D. Spindle disappears

Answer: (A)

The main idea here is when meiosis I finishes. Meiosis I ends when the cell completes division into two separate daughter cells, each with its own nucleus. That means two nuclei form and cytokinesis occurs, producing two haploid cells. This stage comes after homologous chromosomes have been separated in anaphase I and after telophase I, not during the early steps. Crossing over happens earlier, during prophase I, as homologous chromosomes exchange segments. DNA replication happens before meiosis starts, during the S phase, so it isn’t happening at the end. The spindle is used during division and is dismantled as the cells finalize cytokinesis, but the distinct event that marks the end of meiosis I is the formation of two nuclei in two separate cells.