BIOL 103 Chapter Notes - Chapter 19: Transposable Element, Gene Duplication, Retrotransposon
Document Summary
Eukaryotic genomes are usually larger than prokaryotic genomes in both number of genes + genome size. Genome size: total amount of dna; not the same as # of genes. Increased amount of dna correlated w/ increases in cell size, cell complexity, and body complexity. This rule can vary within different species, as well as closely related species. ->eg. similar # of chromosomes, but one species can have nearly double the amount of. ->double amount of dna usually not due to twice as many genes, but repetitive sequences: short dna sequences that are present in many copies --> often abundant in eukaryotic species. Few hundred to several thousand repeats in genome. Sometimes these sequences are multiple copies of the same gene. These sequences play a role in regulation of genes transcription + translation. Found in tens of thousands to millions of repeats in genome. Most sequences have no known f"n + benefit.