BIOL 110 Lecture Notes - Lecture 8: Streptococcus Pneumoniae, Prokaryote, Plasmid
Document Summary
Occurs when prokaryotes acquire genes from the surrounding environment. Dna may have been left over by other bacteria. Foreign dna is directly taken up and expressed. Those that take up dna containing beneficial genes, and reproduce successfully, have a selective advantage over the non-transformed bacteria. Bacteria can be transformed from nonpathogenic into pathogenic (harmful) strains. Ex: harmless streptococcus pneumoniae can pick up cells of a pathogenic strain and become pathogenic. Requires that two living prokaryotic cells physically join together. Direct transfer of genes from one bacterium to another. Male uses an appendage called a pilus (plural, pili) Prokaryotes must have a plasmid term the f factor (fertility factor) to produce pili. If a cell has this, it is f+ F+ is heritable; if a f+ cell divides, both daughter cells will have f+ If a cell doesn"t have this, it is f-
