Weathering and erosion. Weathering is the process where rock is dissolved, worn away or broken down into smaller and smaller pieces. There are mechanical, chemical and organic weathering processes.
What is trinucleotide repeat disorders? A class of genetic diseases that causes expansion of the number of trinucleotide (three base repeats of CG-rich units) within a gene sometimes associated with deleterious consequences.
One of the most well known examples of a short copy number variation is the tri-nucleotide repeat of the CAG base pairs in the Huntingtin gene, the gene that is responsible for the neurological disorder Huntington's disease.