Medical Genetics - V. M. Zaporozhan 2005

Introduction to Medical Genetics
Cytological Foundations of Heredity
Structure and Functions of the Nucleus and Chromosomes - Chemical Composition of Chromosomes

Chromosomes are composed of DNA, basic (histone) Proteins, and acidic (non-histone) proteins. The entire complex of substances making up chromosomes is referred to as Chromatin.

In non-dividing Cells and during the pre-synthetic phase of the interphase in dividing cells, each chromosome contains a single DNA molecule. METABOLISM/36.html">DNA Replication takes place during the synthesis phase of the interphase. From the synthesis phase up to and including metaphase of mitosis, chromosomes contain two DNA molecules. The total length of all 46 DNA molecules located in The Nucleus of a human somatic Cell (within 46 chromosomes) is approximately 190 cm. Consequently, the average length of a single DNA molecule in a chromosome is about 4 cm.

Chromatin also contains RNA molecules, which either represent incomplete Transcription products or perform regulatory, structural, or other Functions.



Last update: 11/08/2026

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