They must give a presentation to teachers and their peers for 10 minutes and take questions. The extended projects are worth the equivalent half an A-level.
A pilot version has been run by Edexcel at around 40 schools, including Rugby, which encourages pupils to look at the wider moral implications of science.
"The perspectives on science courses that we have run have transformed our curriculum," said John Taylor, director of critical skills at Rugby and also chief examiner of the Edexcel extended project.
"It has tremendous potential benefits for both diploma and A-level students. But there is a risk that these benefits could be missed if it is not delivered in an academically rigorous framework."