This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: CHROMOSOMES and KARYOTYPES Chromosomes of higher organisms ( eukaryotes ) contain DNA and protein. One long DNA double helix is present per chromatid DNA is highly organized in association with histones (protein) 5 histones are highly conserved from 1 species to another 4 histones (2 copies of each) make a ball 1 histone links adjacent balls together 146 base pairs of DNA wrap around each ball (2 loops/ball) each ball is a nucleosome Nucleosomes are coiled into solenoids (6 nucleosomes/solenoid) solenoids also coil, forming a fiber fibers coil to give a visible (microscopic) chromosome Chromosomes can best be seen when they are highly condensed at metaphase Stains such as Giemsa that bind to DNA make condensed chromosomes visible Adding colchicine to actively dividing cells destroys spindle fibers and traps the chromosomes at metaphase 04/20/03 6:45 PM CHROMOSOMES Page 1 of 5 http://www.tamu.edu/classes/plan/magill/gene310/chromosomes/CHROMOSOMES.html Individual chromosomes can be cut from a picture and aligned by pairs...
View Full Document
This note was uploaded on 04/29/2008 for the course GENE 310 taught by Professor Magill during the Spring '08 term at Texas A&M.
- Spring '08