BIOL 2153 Chapter : Chapter 9 Extranuclear Inheritance 1
Document Summary
3 kinds of extranuclear inheritance: organelle heredity: organellar dna affects phenotype. Infectious heredity: a cytoplasmic microorganism affects phenotype: maternal effect: nuclear gene products in ooplasm affect phenotype. Organelle heredity: also called non-mendelian inheritance / extranuclear inheritance. Involves genes found in organelle genomes (what organelles?: chloroplasts, mitochondria. Chloroplasts and mitochondria: eukaryotic organelles that have their own genomes, chloroplasts: capture solar energy and store it in carbohydrates, mitochondria: release energy from carbohydrates and convert it to atp, they each have a double-layered membrane. Organelle genome characteristics: most mtdna and cpdna is circular lies within matrix (mt) or stroma (cp) in structures called nucleoid. 16. 5 kb in size: carries 37 genes. 2 genes for large and small rrnas: compact gene arrangement. 75 kb (four times larger than human mtdna) Chloroplast genome: genes closely packed together, contains introns, different from mtdna, more uniform in size, contain more genes than mitochondrial.
