MBG 2040 Chapter Notes - Chapter 6: Homologous Chromosome, Monosomy, Polytene Chromosome

• School: University of Guelph
• Department: Molecular Biology and Genetics
• Course: MBG 2040
• Professor: Schisler/ Mosser

Document Summary

Most cytological analyses is performed on dividing cells, usually in the middle of mitosis. The development of cell culturing techniques has made it possible to study chromosomes in many types of cells. Wbcs: take blood sample, separate cells from serum by centrifugation, remove wbcs and culture in vitro, stimulate cells to divide, disable mitotic spindle, add hypotonic solution to swell cells, squash cells on slide, fix and stain, examine chromosomes. Diploid human cells contain 46 chromosomes- 44 autosomes and 2 sex chromosomes. At mitotic metaphase, each of the 46 chromosomes consists of two identical sister chromatids. The largest autosome is number 1, the smallest is 21, arranged from largest to smallest, with the exception of the second smallest being 22. The x chromosome is intermediate in size, with the y being about the same as 22. The centromere divides each chromosome into long and short arms. The short arm is denoted by p (for petite) and the long is q.