mutation

• What is a mutation?

  A change in the DNA sequence
• What is aneuploidy?

  An abnormal chromosome number due to nondisjunction
• What condition is associated with trisomy 21?

  Down syndrome
• Why are structural mutations considered more dangerous?

  They alter the entire chromosomal structure
• What is the result of point mutations?

  They change the amino acid sequence
• How can a single base substitution in hemoglobin affect health?

  It can cause sickle cell disease
• What is a nonsense mutation?

  It produces a stop codon in mRNA
• How does a frameshift mutation affect protein synthesis?

  It changes the reading frame of mRNA
• What are the causes of mutations?

  • Inherited from parents (if carriers)
  • Environmental agents (mutagens)
  • Spontaneous occurrences
• What is a carcinogen?

  A substance that causes cancer
• What is the mRNA transcript for the DNA sequence TAC ACC TTG GCG ACG ACT?

  AUG UGG AAC CGC UGC UGA
• How does the mutation in the second DNA sequence affect the amino acid sequence?

  It results in no stop codon
• What is the effect of a frameshift mutation on a sentence analogy?

  • Changes the 'reading frame'
  • Example: "The fat cat ate the old rat" becomes "The fat caat tet heo Idr at."