MEDICAL BIOLOGY, ANATOMY, HUMAN PHYSIOLOGY AND PATHOLOGY - Ya.I. Fedoniuk 2010

BIOLOGY

SECTION 1. BIOLOGICAL FOUNDATIONS OF HUMAN VITAL ACTIVITY

1.3. MOLECULAR-GENETIC AND CELLULAR LEVELS OF LIFE ORGANIZATION

1.3.2. Structural, chemical, and functional organization of eukaryotic cells

The Nucleus: The Central Information Apparatus of the Cell

The Nucleus (Latin: nucleus, Greek: karyon - nucleus) is an essential component of The Introduction/5.html">Eukaryotic Cell that performs genetic Functions and regulates all Cellular metabolic processes. Both functions are associated with the DNA of the nuclear Chromosomes. DNA is the hereditary (genetic) material and the carrier of Genetic information. The nucleus ensures the storage, Replication, expression, and transmission of hereditary information to daughter nuclei. It is the site of synthesis for all types of RNA (METABOLISM/31.html">Transcription) and ribosomal subunits. The nucleus controls cellular metabolism through the expression (activity) of relevant genes. Together, the nucleus and Cytoplasm form a unified, interconnected system in a state of dynamic equilibrium. Each cell type maintains a constant nucleocytoplasmic ratio (Hertwig's index). If this ratio is disrupted, The Cell either undergoes division or may die. Nuclei are most commonly spherical in shape, though other shapes may occur. Their size typically ranges from 3-4 to 40 µm. The nucleus was first discovered in 1831 by the English botanist R. Brown in plant Cells of the Orchid family.



Last update: 08/08/2026

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