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Unformatted text preview: hromosomal DNA temporary conjugation bridge (sex pilus)
Figure 27.12 (Campbell et al 9th ed) Vertical gene transfer
Transfer of genes from parent to offspring 31 Horizontal gene transfer
Transfer of genes to another organism
not via reproduction
• HGT moves genes within & btwn species.
Can occur btwn spp of different domains!
Important in evolution of many organisms
Responsible for antibiotic resistance among
bacteria species. BACTERIA Horizontal transfer from Bacteria / Archaea to Eukaryotes 32 C.D.C. states antibiotic resistance one of
the world’s largest health problems •Indiscriminate use of antibiotics leads to resistant forms of pathogenic bacteria
•Antibiotic misuse includes: over prescription, misuse by patients,
antibiotics in animal feed, and cleaning products 33 36 Archaea vs Bacteria Similarities
• Flagella present
• No nucleus and few organelles
• Circular chromosome
• No introns in most genes
• Ribosomes same size Differences
• Archaea cell walls w/o peptidoglycan
-Chemically and structurally diverse
-Growth not inhibited by antibiotics
• Lipids in cell membrane differ
• Flagella structurally very different
• Archaea RNA polymerase more complex
• Translation start codons differ 37 Archaea vs Eukarya Similarities
• DNA w/ similar proteins
• RNA polymerase similar
• Translation start codons similar 38 Archaea Diversity
• 1st classified as a subgroup of bacteria in 1977
• Little known about their diversity and phylogenetic relationships...
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