BIOL 202 Lecture Notes - Lecture 14: Mutation, Lactose Intolerance, Mitosis
31 Oct 2018
School
Department
Course
Professor
Document Summary
Process of turning on and off, or turning up and down the level of gene expression. Activator proteins promote transcription (positive control, on switch) Repressor proteins inhibit transcription (n2egative control, off switch) Mrna can be degraded rapidly (negative control) Cons: can cause inherited disorders, can cause cancer. Pros: can create new forms, mutations are necessary for evolution to occur. Mutagens: increase mutation rates (smoking, uv light, radiation) Spontaneous mutations: changes can happen when dna duplicates during cellular reproduction. Most mistakes are corrected by repair mechanisms but some remain. There is nothing we can do to avoid it. Radiation-induced mutations: radiations with enough energy can disrupt atomic structure of chromosomes (ultraviolet, x rays, etc. ) Somatic mutations: mutations in somatic or body cells. Defective lactase cannot break lactose (milk sugar) New cells are generated by cell division. Cells must accurately duplicate and distribute genetic materials (chromosomes) into daughter cells. Contain 46 chromosomes (44 non-sex chromosomes, 2 sex chromosomes)
