BIOL 200 Lecture Notes - Lecture 12: Dna Barcoding, Sea Slug, Non-Coding Rna
Document Summary
Originally free organisms that were endocytosed and became endosymbionts. Resemble prokaryotes in terms of their genomes: circular, genes typically lack introns, gene products resemble prokaryotic rnas and proteins. There are usually many mitochondria (and chloroplasts) per cell. Each organelle may have multiple genomes: dual staining of a euglena cell highlights positions of where dna is located. Mitochondria (many small dots - many mitochondria) Mitochondria: many copies of mitochondrial genome inside of it. Chloroplast: multiple copies of chloroplast"s genome inside of it. Endocytosis process lead to incorporation of mitochondria/chloroplasts into cells: independent for mitochondria and chloroplasts. Original endosymbiont might have had a large genome but over evolutionary time a lot of genes in organelle went missing (in mitochondria/chloroplasts) Endocytosis introducing endosymbiont into eukaryotic cells: sea slug eats algae and relocates chloroplasts of algae into own epidermal cells -> can then photosynthesize.
