A
1 Structure and Function of the Human Genome
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Fig. 6. Structure of chromosomes. For details see text. (Modified from [1).)
• There are about 80,000 expressed genes present in the human genome.
• scale for the dimensions of genomic DNA structures in base pairs is
shown in Figure 7. For structural entities of different sizes the appropriate methodology for the study of its molecular structure is indicated.
Functions of the Human Genome
Replication
Cell division during mitosis and gametogenesis during meiosis require
prior replication (or "reduplication") of the haploid set of chromosomes.
The so-called bivalent chromosomes are built from the set of 46, XY. The
bivalents each consist of 2 sister chromatids which are joined at the centromer. Replication occurs in the S-phase of the cell cycle.