BIOL1020 Lecture Notes - Lecture 7: Intracellular Parasite, Rna Virus, Dna Replication
Document Summary
Viruses: range in size from 20-400nm, can also cause cancer (papillomavirus, genome size: 4000-400,000 nt, human: 3 billion nt, has nucleic acid, protein capsid, envelope, not a living organism, think of them as nuclear-protein particles, have diverse morphologies. Stages of a virus lifecycle: attachment, penetration, uncoating, transcription/translation, genome replication, assembly, release. Principles of heredity: all individuals of a species have the same base set of genes (variation due to gene. Mutations: changes in genotype arise from mutation of genomic dna, mutations are changes in the dna sequence, point mutations: single nucleotide (nt) changes, translocations, deletions or duplications: large scale chromosomal changes. Cancer is the outcome of mis-regulation of the cell cycle caused by genetic mutations. Most cancers are somatic (e. g. skin cancer), and are therefore not heritable. Some cancer-causing mutations are in the germ line, and therefore heritable (e. g. some breast and ovarian cancers) In humans, the mutation rate is ~1 in every 2x108 bases, or about 100-
