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.
More About Trinucleotide Repeat. The DNA sequence of some genes contain trinucleotide repeats, like CAG, CAG, CAG. Normally, if a gene has on the order of a dozen repeats, there is not a problem. The expansion of these repeats, however, are associated with several different diseases. The repeats can expand during DNA replication.