Home of real teaching & learning
  • Full support for teachers
  • Focus on critical thinking
  • Engaging classroom activities
  • Integrated student eBook
  • Assessed tasks / qBank
  • Practice exam questions

The InThinking Guarantee: Our sites are written by expert practitioners and not by AI

See our AI policy

Disclaimer: InThinking subject sites are neither endorsed by nor connected with the International Baccalaureate Organisation.

Don't miss out, find out!

Endosymbiosis - Nature of Science (2025)

The idea that 3 billion years ago a simple cell engulfed a free-living prokaryote cell, kept it alive and became a eukaryote cell with a mitochondria is difficult to ‘prove’. There are hypothesis that try to explain the origin of the first eukaryote cells. There are predictions and supporting evidence too. The theory of Endosymbiosis is a great illustration of the nature of science. This story of a biologist’s...

Help