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.
PCR makes copies of the DNA much like DNA copies itself in a cell, producing almost any desired amount of the genetic material. Once the DNA in question has been amplified, STR analysis examines how often base pairs repeat in specific loci, or locations, on a DNA strand. These can be dinucleotide, trinucleotide, tetranucleotide or pentanucleotide repeats -- that is, repetitions of two, three, four or five base pairs.