BIOL108 Lecture Notes - Lecture 13: Geologic Time Scale, Cambrian Explosion, Mesozoic

• School: University of Alberta
• Department: Biology (Biological Sciences)
• Course: BIOL108
• Professor: Richard Moses

Document Summary

Silurian: cambrian (cambrian explosions, ordovician, devonian, carboniferous, permian (extinctions, mesozoic era (250 - 60 mya, triassic period. Speculative, but supported by experimental evidence: all life shares: dna and rna, membrane structure, chnops atoms, amino acids, protein enzymes, carbohydrates, fatty acids, atp for energy, suggests all life came from one origin. First life - prokaryotic: two of the three domains of life are prokaryotes (archaea and bacteria, archaea more closely related to eukaryotes than prokaryotes, photosynthetic bacteria (cyanobacteria) contributed to the accumulation of oxygen, archaea. Ex. stromatolites are accumulated biofilms: not considered to be multicellular, many are symbionts in eukaryotic hosts. Symbiosis - long-term relationship between different species in direct contact: mutual, commensal, parasitic/pathogenic, mutualism examples - n-fixing nodules on legume roots, species in people"s digesti(cid:448)e s(cid:455)ste(cid:373)s, (cid:271)iolu(cid:373)i(cid:374)es(cid:272)e(cid:374)t (cid:271)a(cid:272)teria in deep-sea organisms (angler fish) Some species have specialized membranes from plasma membrane folding into the cell.