Yes, we can see chromosomes, but only when cells are dividing.
During the normal state of a cell's life, when it's not undergoing division (interphase), the DNA that makes up chromosomes is loosely packed and spread throughout the nucleus. In this state, chromosomes are not visible, even with a microscope.
However, when a cell prepares to divide (mitosis or meiosis), the DNA undergoes a dramatic transformation. It condenses and coils very tightly, forming the distinct, rod-shaped structures we recognize as chromosomes. This compaction makes them thick enough to be observed under a microscope, especially when stained with dyes that bind to DNA.
Here's a breakdown:
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Interphase (Cell Not Dividing): DNA is in a relaxed, less condensed state called chromatin. Chromosomes are not individually distinguishable under a microscope.
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Cell Division (Mitosis/Meiosis): DNA condenses into tightly packed chromosomes. These chromosomes become visible under a microscope, particularly when stained.
Therefore, the visibility of chromosomes is dependent on the cell's stage in the cell cycle. We can see them clearly during cell division thanks to the condensation process.
