Mutations

• types of substitution mutations:

  missense, nonsense, splice-site
• Which type of gene mutation occurs when a codon for an amino acid is replaced by a stop codon?

  Nonsense mutation
• Which of the following terms describes types of mutation which occur in both genes and chromosomes?

  deletion
• Which of these gene mutations is the result of

  single-nucleotide substitution?

  nonsense, and frame-shift
• what is missense mutation

  one amino acid codon is

  replaced with another
• what is nonsense mutation

  one amino acid codon is

  replaced with a stop codon
• what is splice site mutation

  exon-intron codons are created

  or destroyed
• Describe how the genetic code for glycogen synthase might be altered in an individual with the

  disease.

  It will contain a different nucleotide/ base
• Explain why this altered genetic code fails to produce glycogen synthase.

  The shape/active site of the enzyme will change
• Describe how the genetic code for glycogen synthase might be altered in an individual with the disease.

  It will contain a different nucleotide/base
• Explain why this altered genetic code fails to produce glycogen synthase.

  The protein synthase contains a different amino acid(s).
• A genetic condition in a family is caused by a mutation in which an extra nucleotide is inserted into the gene that codes for an enzyme. Explain the likely effect of this mutation on the structure of the enzyme.

  The order of amino acids is changed from that point OR Different amino acids in enzyme

  The active site of the enzyme will change
• What general term is used to describe a gene alteration?

  Mutation.
• How might the structure of the gene which codes for dystrophin be altered?

  change the order of bases
• Sickle cell disease is caused by a substitution mutation in the gene that codes for haemoglobin.

  1. Describe how this form of mutation affects the structure of a gene.

  It alters the (DNA) nucleotide sequence
• Describe chromosome structure mutations and the consequence of these to the individual.

  These mutations can be lethal