definition

• Any change in the genetic information
• somatic [cells which will, or have already, differentiated to body parts]:
• may produce patches of unusual characteristics
• may produce unusual growth patterns
  cancerous, pre-cancerous, or benign
• will not affect offspring
• germ line [cells destined to become gametes]:
• will not affect individual
• may produce unusual characteristics in offspring
• inheritable!

causes

• ionizing radiation
• absorbed photon transfers energy to electron, shifting to higher shell
• if electron is in covalent bond, can break bond
• deoxyribose-base bond broken
  repaired by substituting new base
  repaired by deleting entire nucleotide
• chemical

types

• point mutation
• affect one to a few base pairs [adjacent]
• chromosomal rearrangements
• affect longer segments
• deletions
• insertions
• inversions

effects

• silent
• changes produce "synonyms" for AA
• altered protein retains normal function
  usually means incorrect AA is not at critical location
• missense
• valid protein but with incorrect function
• nonsense
• non-functional protein successfully made
• unable to make a protein

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© 2004-2005 TwoOldGuys ™

revised 19 aug 2006