BIOSC 0160 Lecture Notes - Spindle Apparatus, Adult Stem Cell, Microtubule Organizing Center
Document Summary
One exception is localized mrna: functions, reproduction (only in certain species) Increases the size of structures: tissue maintenance/repair. Chromosomes and chromatin: the eukaryotic chromosome, linear (unlike bacteria, which have circular chromosomes, complex of dna and protein called chromatin, bears genes, found inside the nucleus. Undergoes condensation and relaxation: also bears non-genic dna (heterochromatin, chromosome number varies between species (humans have 46, chromatin, dna-protein complex that makes up chromosomes, functions: Regulation of gene expression: packing hierarchy: Most basic level: dna wrapped around nucleosome like beads string, nucleosomes have four histomes (h2a, h2b, h3, h1 attaches dna. Next level: h1 binds to next nucleosome, can cause 30 to form, no linker dna. 1/7: fiber becomes part of a large looped domain on a protein scaffold (super packed) Next level: fully condensed, protein scaffold folds up, karyotypes, array of chromosomes that a person"s cells bear, or a picture of that array. Labeled from largest to smallest autosomes with sex chromosomes at the end.
