BIOL 2002 Chapter Notes - Chapter 15: Centromere, Metaphase, Trisomy
Document Summary
Chromosomes occur in sets and 2 sorting processes determine the chromosome number following cell division. Geneticists discovered that variation in chromosome structure and number can have major effects on organisms. Has been an important factor in the evolution of new species. Structure and number of chromosomes among different species varies greatly. Within a species there is size and shape variation. An abnormality is when the structure or number of chromosome changes within the species. Chromosome composition within a species is relatively constant. Cytogeneticists have various ways to classify and identify chromosomes in their metaphase form. Centromeres have a short and long arm. Short arm is p and long arm is q. Banding patterns - revealed when treated with stains. Can distinguish individual chromosomes and to detect changes in structure that was caused by mutation. Chromosomal mutations involved the breaking and rejoining of chromosomes. Simple translocation moves a segment of 1 chromosome to another.
