IB past paper analysis

Biology HL
May 2025 · Paper 1 · TZ1

See what this paper tests, focus on the skills that carry the marks, and practise matched Exam Vault questions with AI marking.

Original Exam Vault questions with AI markscheme feedback for this topic.

Switch paper
  • 40questions
  • 75marks
  • 61question parts
  • 56micro-topics

What this paper tests

Mark distribution

  • Continuity and change25%
  • Unity and diversity24%
  • Interaction and interdependence23%
  • Form and function20%
  • Experimental and data skills8%

Hardest areas (by marks)

  1. 1.Base and amino acid sequences as the basis for constructing cladograms4 marks

Question types

identify: 69%explain / justify: 8%write down / state: 5%outline: 3%0%
  • identify69%
  • explain / justify8%
  • write down / state5%
  • outline3%

0% of parts are show / prove.

View all Biology HL past papers →

Questions in this paper

Open a question to see what each part tests, how often that micro-topic comes up, and practise matched questions.

Where to go next

Good to know

Can I download Biology HL May 2025 TZ1 Paper 1 here?

No. The paper and its mark scheme belong to the IB and are not reproduced. This page gives the structure of every question (marks, command term, micro-topic, the skill tested), the exam analysis, and practice questions we wrote to test the same skills. Subscribers can also open our summary of how each part's marks are awarded.

Which topics dominate May 2025 TZ1 Paper 1?

Continuity and change 25% (typical 28%), Unity and diversity 24% (typical 19%), Interaction and interdependence 23% (typical 26%).

How do I practise this paper without the paper?

Press "Practise similar" on any question. We open questions matched by micro-topic, command term and mark range with model answers and AI marking, then bring you back here.

Want to practise the skills from this paper?

Open original Exam Vault questions matched by topic, marks and command term, with AI marking and step-by-step feedback.

All Biology HL past papers