SL Content Statements

• D1.3.1

  Gene mutations as structural changes to genes at the molecular level

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  Distinguish between substitutions, insertions and deletions.

• D1.3.2

  Consequences of base substitutions

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  Students should understand that single-nucleotide polymorphisms (SNPs) are the result of base substitution mutations and that because of the degeneracy of the genetic code they may or may not change a single amino acid in a polypeptide.

• D1.3.3

  Consequences of insertions and deletions

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  Include the likelihood of polypeptides ceasing to function, either through frameshift changes or through major insertions or deletions. Specific examples are not required.
  

• D1.3.4

  Causes of gene mutation

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  Students should understand that gene mutation can be caused by mutagens and by errors in DNA replication or repair. Include examples of chemical mutagens and mutagenic forms of radiation.

• D1.3.5

  Randomness in mutation

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  Students should understand that mutations can occur anywhere in the base sequences of a genome, although some bases have a higher probability of mutating than others. They should also understand that no natural mechanism is known for making a deliberate change to a particular base with the purpose of changing a trait.

• D1.3.6

  Consequences of mutation in germ cells and somatic cells

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  Include inheritance of mutated genes in germ cells and cancer in somatic cells.
  

• D1.3.7

  Mutation as a source of genetic variation

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  Students should appreciate that gene mutation is the original source of all genetic variation. Although most mutations are either harmful or neutral for an individual organism, in a species they are in the long term essential for evolution by natural selection.
  NOS: Commercial genetic tests can yield information about potential future health and disease risk. One possible impact is that, without expert interpretation, this information could be problematic.