IB Diploma Biology HL, topic A3
Organisms (Unity and diversity)
This topic asks what a species is and how the variety of living organisms is named, compared and classified. It covers species concepts, chromosome numbers, karyograms and genomes, then (HL) dichotomous keys, environmental DNA and the cladistic methods used to classify organisms by evolutionary relationships.
Revision notes
Worksheet
FlashcardsSubtopics
Work through them in order. Each one has notes, exam questions and flashcards, and a PDF of each.
- 1Diversity of organisms Spec A3.1IB Biology A3.1: variation, species concepts, binomial names, chromosome numbers, karyograms, genome diversity and whole genome sequencing.NotesQuestions 9Flashcards 24
- 2Classification and cladistics HL onlySpec A3.2IB Biology A3.2 (HL): why we classify, the traditional hierarchy, clades, molecular clocks, building and analysing cladograms, and the three domains.NotesQuestions 7Flashcards 14
Whole topic
When you have done the subtopics: test yourself on everything, or print the lot.