Biology · Continuity and change

D1.3 — Mutations and gene editing

Biology · SL / HL · syllabus-mapped notes

1. D1.3.1

   Gene mutations as structural changes to genes at the molecular level

   Define gene mutation, and distinguish substitution, insertion and deletion.

2. D1.3.2

   Consequences of base substitutions

   Explain same-sense, nonsense and mis-sense substitutions, and what SNPs are.

3. D1.3.3

   Consequences of insertions and deletions

   Explain why insertions and deletions cause frameshifts, and why that is so damaging.

4. D1.3.4

   Causes of gene mutation

   Explain how radiation and chemical mutagens increase mutation rate.

5. D1.3.5

   Randomness in mutation

   Explain what randomness in mutation does and does not mean.

6. D1.3.6

   Consequences of mutation in germ cells and somatic cells

   Contrast the consequences of mutation in germ cells and in somatic cells.

7. D1.3.7

   Mutation as a source of genetic variation

   Explain why mutation is the original source of all genetic variation, and why it is needed.

8. D1.3.8

   Gene knockout as a technique for investigating the function of a gene by changing it to make it inoperative

   Explain gene knockout as a way of discovering a gene's function.

9. D1.3.9

   Use of the CRISPR sequences and the enzyme Cas9 in gene editing

   Explain what CRISPR sequences are and how Cas9 uses guide RNA to cut target DNA.

10. D1.3.10

    Hypotheses to account for conserved or highly conserved sequences in genes

    Give two hypotheses that account for conserved and highly conserved sequences.