1. **Stating the problem:** Compare and contrast the appearance of a cell during prophase and interphase in mitosis. 2. **Understanding the stages:** - **Interphase:** The cell prepares for division. Chromosomes are not visible as distinct structures; DNA is in a relaxed, uncondensed form called chromatin inside the nucleus. - **Prophase:** Chromosomes condense and become visible as distinct X-shaped structures, each consisting of two sister chromatids joined at a centromere. The nuclear envelope begins to break down. 3. **Key differences:** - In interphase, the nucleus is intact and chromosomes are not visible. - In prophase, chromosomes are condensed and visible as X-shaped structures. - The centromere is visible in prophase, holding chromatids together. - Spindle fibers start to form in prophase, which are absent in interphase. 4. **Summary:** - Interphase shows a cell with a clear nucleus and uncondensed chromatin. - Prophase shows condensed chromosomes with chromatids joined at centromeres and spindle fibers forming. This explains how prophase looks different from interphase in mitosis.