BIOL 1202 Chapter : Biology 12012
Document Summary
End of chapter questions at end of chapter 26. Mosaic plant virus: 3 common parts of viruses, 1. Can be either single- stranded or double stranded dna or rna: 2. Capsid- protein coat which surrounds and protects genome: 3. Envelope- membrane (phospholipid bilayer) which surrounds the capsid: hijack cells, highly specific for organisms it infects. Viruses evolve: when you get the flu vaccine, injects a strand of the inactive form of the flu. Cannot get the flu from being injected by the flu: hiv is impossible to beat in humans. 1000 of genomes of hiv in body making it impossible to overcome. Three lines of defense against microbial attack: innate defense, nonspecific external barriers, nonspecific internal barriers, acquired immunity, specific immune response. Three lines of defense: external barriers (skin, mucous membranes, a. Skin: physical barrier to microbial entry: inhospitable environment for growth; dry, dead cells at surface. Sweat/sebaceous glands secreting acids & natural antibiotics like lactic acid.
