When do tetrads form?

When do tetrads form?

• A. Metaphase I
• B. Anaphase II
• C. Prophase I
• D. Telophase I

Answer: (C)

Tetrad formation happens when homologous chromosomes pair up during prophase I of meiosis. This pairing, called synapsis, brings the maternal and paternal homologs together so each already replicated chromosome (with two sister chromatids) forms a group of four chromatids—the tetrad. This arrangement sets the stage for crossing over and for the later separation of homologs in meiosis I. By metaphase I the tetrads are aligned at the cell’s center, but the actual formation occurs during prophase I.

Tetrad formation happens when homologous chromosomes pair up during prophase I of meiosis. This pairing, called synapsis, brings the maternal and paternal homologs together so each already replicated chromosome (with two sister chromatids) forms a group of four chromatids—the tetrad. This arrangement sets the stage for crossing over and for the later separation of homologs in meiosis I. By metaphase I the tetrads are aligned at the cell’s center, but the actual formation occurs during prophase I.