The nucleus is the cell's control center and the repository of its genetic information. It's the defining feature separating eukaryotic cells (like those in plants and animals) from prokaryotic cells (like bacteria).
Key Functions of the Nucleus:
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Houses the Cell's Genome: The nucleus safeguards the cell's DNA, organized into chromosomes. This DNA contains the instructions for building and maintaining the organism. [Source: Britannica] Chromosomes, made of DNA tightly coiled around proteins, reside within the nucleus. [Source: JAX]
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Controls Cell Activity: By housing the genetic information, the nucleus dictates the cell's functions and activities. It regulates gene expression, determining which proteins are synthesized and when. [Source: NCBI Bookshelf]
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mRNA Production and Regulation: The nucleus plays a crucial role in mRNA production. Though mRNA from vaccines, for example, doesn't enter the nucleus or alter DNA, the nucleus is the origin point for cellular mRNA production. [Source: MedlinePlus]
Note: Some references mention specific nuclei within the brain (like the nucleus accumbens or pedunculopontine nucleus) which have specialized roles related to pleasure and movement control, respectively. However, these are specialized structures, not the fundamental cellular nucleus described above. [Source: PubMed, Neurology]
