BIOL 1002 : Bio 1002 Test 2
Document Summary
Viroids: even simpler and smaller than viruses, fragment of rna, hijack cells; infects primarily plant cells including citrus trees, potatoes, avocados. Prions: protein particle with no genetic material (i. e. dna or rna) Prokaryotes: bacteria and archaea domains, 12000 species described, may be 100-1000x that number, 1st organisms to appear on earth, 3. 5 billion years ago. Prokaryotes (bacteria: cell wall, semi-rigid, permeable, made of peptidoglycan (carbohydrate with amino acids attached). Protective resting structures bacteria surrounded by durable cell wall. Resistant to extreme conditions: reproduction, asexual in the form of binary fission, sexual in the form of conjugation using plasmids, energy sources, autotrophs using photosynthesis or chemosynthesis, heterotrophs including symbiotes, diseases, gonnoreaha,, lymes, antibiotic resistance. Archaea vs bacteria: similar to bacteria in many respects, single-celled, prokaryotes, small size, different in their, cell membrane lipids structure, cell wall composition. **no peptidoglycan in their cell walls*: rrna subunit sequences.
