BIOL240 Chapter Notes -16S Ribosomal Rna, 18S Ribosomal Rna, Ribosomal Rna
Document Summary
Part a: theories on the origins of life. Rna form of life may be precursor to modern cellular forms of life. Rna acts as intermediary between protein and dna. The evolution of the earth and the first life forms. Molecules of rna polymer developed ability to replicate. Universal ancestor bacteria and archaea nuclear line increase in cell size primitive eukaryote and origin of nucleus. Endosymbiosis modern eukaryotes lacking mitochondria and primitive mitchondria. Determining how organisms are related to each other. Special portions of genome make dna comparisons. Ribosomal rna encoding gee or 16s ribosomal dna. Part b: ribosomal rna as an evolutionary chronometer. 16s ribosomal rna standard molecular chronometer used to determine phlogeny. All organisms have either 16s or 18s ribosomal rna. Mutations arise spontaneously at given rate so more mutations present over time. Primers: short single-stranded nucleotide strands designed to base pair to conserved regions of gene. Amplication product results from many pcr cycles.