Virginia Biology SOL Practice Test

During mitosis, chromatin condenses to form distinct chromosomes, and this process occurs in the nucleus. The nucleus is the organelle in eukaryotic cells that houses the cell's genetic material, organized as chromatin. As the cell prepares to divide, the chromatin undergoes a series of structural changes, becoming more tightly coiled and compacted to form the visible chromosomes that are essential for ensuring that DNA is accurately replicated and distributed to the daughter cells.

This organization into chromosomes is crucial during cell division, as it allows for the equal partitioning of genetic material. In contrast, the cytoplasm is where various cellular processes occur but does not involve the organization of chromatin. The cell membrane serves as a barrier that encloses the cell and does not play a role in the condensation of chromatin. Ribosomes are the sites of protein synthesis and are not involved in DNA organization or mitosis. Thus, the nucleus is the correct location where chromatin condenses into chromosomes during mitosis.