LIFE 102 Lecture Notes - Gene Duplication, Chromosomal Rearrangement, Homeobox
Document Summary
Concept 21. 5: duplication, rearrangement, and mutation of dna contribute to genome evolution. The rate of duplications and inversions seems to have accelerated about 100 million years ago. This coincides with when large dinosaurs went extinct and mammals diversified. Chromosomal rearrangements are thought to contribute to the generation of new species. Some of the recombination hot spots associated with chromosomal rearrangement are also locations that are associated with diseases. Unequal crossing over during prophase i of meiosis can result in one chromosome with a deletion and another with a duplication of a particular region. Transposable elements can provide sites for crossover between nonsister chromatids. Homeotic genes are genes that determine how different regions of the body develop. Hox genes in animals are important for segmentation. Mads-box genes in plants are involved in flower development. Molecular analysis of the homeotic genes in drosophila has shown that they all include a sequence called a homeobox.
