IB Biology: A3.2 Classification and cladistics (first exams in 2025)

This lesson can be purchased as part of the IB Complete course bundle (first exams 2025) at a heavily discounted price, formed of 40 fully resourced lessons, end of topic exams and student checklists. It can be found here

This PowerPoint contains everything you need to teach the A3.2 Classification and cladistics in the new IB Biology specification (HL only)
This Powerpoint consists of 50 slides and contains the followings:
All the information ( HL) the IB have included in the new spec.

Exam tips
Clear diagrams
Videos
Student research tasks
Clearly identified HL and SL content
The following content is included:
A3.2.1: Explain why a classification system is needed. (HL only)
A3.2.2: Describe difficulties with the traditional hierarchy of taxa. (HL only)
A3.2.3: Describe the advantages of basing classification on evolutionary relationships. (HL only)
A3.2.4: Define a clade. (HL only)
A3.2.5: Explain how the gradual accumulation of sequence changes can be used to determine the time since a common ancestor diverged into extant species (HL only)
A3.2.6: Describe how base or amino acid sequences can be used in the construction of cladograms. (HL only)
A3.2.7: Deduce evolutionary relationships from cladograms. (HL only)
A3.2.8: Describe how cladistics can be used to assess whether classifications correspond to evolutionary relationships. (HL only)
A3.2.9: Describe how the analysis of rRNA base sequences led to the introduction of the domain taxa. (HL only)