23: Chromosome Structure
- Page ID
- 15188
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- 23.1: Gene Mapping and Chromosomal Karyotypes
- Genes provide instructions to build living organisms and each specific gene maps to the same chromosome in every cell. This physical gene location within the organism's chromosomes is called the gene loci. If two genes are found on the same chromosome, especially when they are in close proximity to one another, they are said to be linked.
- 23.2: DNA Transposable Elements
- Eukaryotic genomes contain an abundance of repeated DNA, and some repeated sequences are mobile. Transposable elements (TEs) are defined as DNA sequences that are able to move from one location to another in the genome. TEs have been identified in all organisms, prokaryotic and eukaryotic, and can occupy a high proportion of a species’ genome.
- 23.3: Chromosome Packaging
- Most eukaryotic chromosomes include packaging proteins which, aided by chaperone proteins, bind to and condense the DNA molecule to prevent it from becoming an unmanageable tangle. Before typical cell division, these chromosomes are duplicated in the process of DNA replication, providing a complete set of chromosomes for each daughter cell.