IB Biology HL 1.3.1 Gene mutations and sequence consequences Question Bank
Practise IB Biology HL 1.3.1 by analysing gene-mutation types and their consequences for alleles and gene products.
- Syllabus
- First assessment 2025
- Course
- Biology HL
- Level
- HL
Practise IB Biology HL 1.3.1 by analysing gene-mutation types and their consequences for alleles and gene products.
Duchenne muscular dystrophy (DMD) is a sex-linked genetic disorder caused by a recessive allele resulting from mutations in the X-linked dystrophin gene. This causes the degeneration of cardiac and skeletal muscle. These mutations can include deletions, insertions and base substitution mutations.
Distinguish between deletion and insertion mutations.

deletion is loss/removal of bases/nucleotides/part of DNA/gene while insertion is addition of bases/nucleotides/one/more copies of any piece of DNA/gene/chromosome;
Both deletion and insertion needed.
Marking guidance:
Do not award marking point for repeating the definition e.g. "deletion" is bases "deleted" / "insertion" is bases "inserted".