New chromosomes remain attached to cell membrane

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new chromosomes remain attached to cell membrane

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LectureNotes said new chromosomes remain attached to cell membrane

Answer: The statement that “new chromosomes remain attached to the cell membrane” appears to be a misunderstanding of cellular processes. In eukaryotic cells, chromosomes are not attached to the cell membrane but rather organized within the nucleus. Let’s break down what typically happens with chromosomes during cell division.

Chromosome Organization

  1. Interphase:

    • During most of a cell’s life (interphase), chromosomes are relaxed forms of DNA known as chromatin, and they are primarily localized in the nucleus.

  2. Prophase:

    • In preparation for cell division, during prophase of mitosis, chromosomes condense and begin to become visible under a microscope.

  3. Metaphase:

    • Chromosomes align along the metaphase plate, a central plane within the cell. Microtubules, which are part of the mitotic spindle, attach to the chromosomes at their centromeres through structures called kinetochores.

  4. Anaphase:

    • Sister chromatids (identical copies of a chromosome) are pulled apart by the spindle fibers towards opposite poles of the cell.

  5. Telophase:

    • New nuclear membranes form around each set of separated sister chromatids, now individual chromosomes, creating two nuclei within the cell.

  6. Cytokinesis:

    • Finally, the cell membrane pinches inwards (in animal cells) or a cell plate forms (in plant cells), dividing the cell into two distinct daughter cells.

Attachment to Membrane

In prokaryotic cells (such as bacteria), the process is somewhat different. Their simpler structure lacks a nucleus and involves direct replication and attachment mechanisms:

  • Binary Fission:
    • In bacteria, DNA replication and cell division occur through a process called binary fission. The singular circular chromosome is attached to the cell membrane, and as the cell grows, it pulls the two DNA copies apart, followed by the cell dividing into two.

Conclusion

Therefore, in the context of typical eukaryotic cell division, chromosomes do not remain attached to the cell membrane. They are instead managed within the nuclear and cytoplasmic processes during mitosis and eventually packaged into new nuclei. However, in prokaryotic cells, the attachment of the chromosome to the cell membrane during binary fission is a crucial part of cell division.

If you have more detailed context or specific queries about this process, feel free to ask!