The simplest answer is that Gateway Science takes the traditional conceptual approach similar to that taken by the other GCSE sciences from the other exam boards. Twenty First Century Science is context led (related to everyday application of science) and available as separate science GCSEs in addition to Combined Science GCSE (unlike AQA Synergy).
Gateway Science grew out of Suffolk Science and the assessments continue to reflect the approach of that earlier teacher led initiative. In Gateway Science question papers the approach taken is to ask questions in real science contexts, make it clear what science is being assessed and avoid unnecessary language in the question stems. Gateway question papers use MCQs (multiple choice questions).
Twenty First Century Science was originally developed by the University of York Secondary Education Group (UYSEG) who are also associated with a range of other contextual curricula including Salters Chemistry. UYSEGs provide an independent set of support resources for C21 Science through OUPs Kerboodle platform. The C21 Science specifications have taken the DfE mandatory content statements and grouped the science content into Learning Objectives ("spec statements") that read the way science teachers expect them to look (this does not increase the content, however it does mean greater clarity for teachers). In C21 Science question papers the approach taken is to ask questions in real science imbedded in realistic contexts, make it clear what science is being assessed so you will find more developed contexts running through a series of question items. C21 Science question papers do not use MCQs (multiple choice questions). However they do use a variety of other objective questioning approaches such as circling words, tick boxes, etc.
For both Gateway and Twenty First Century we have redesigned the assessments to increase their accessibility for both foundation and higher tier candidates. We have summarised our accessibility principles and how they work in two short booklets that can also help students to understand how OCR science question papers work:
If you would like to speak to one of our Science Subject Advisors then please either call in (01223 553998) or email us (firstname.lastname@example.org) with contact details and a time that we can phone you.