The 20 free marks hiding in your Edexcel IAL Biology Unit 5 exam — and how to claim every single one

Unit 5’s scientific article isn’t “extra reading”—it’s a mark bank. Students lose easy marks by summarising instead of analysing variables, trends, and limitations.

TL;DR The Edexcel IAL Biology Unit 5 exam (WBI15/01) includes a 20-mark question built entirely around a pre-released scientific article that students receive weeks in advance. Most students underuse it. This post explains exactly how the article question works, what the June 2026 article covers, and how to prepare for it systematically — so you walk in having already answered most of Question 8 in your head.

Unit 5's scientific article is not "extra reading" — it is a mark bank. Students lose easy marks by summarising instead of analysing variables, trends, and limitations. Think of the article question as an open-book practical: identify the research question, define the key variables, and interpret what the data is trying to show in plain English. A reliable structure is: what they tested, how they measured it, what the results suggest, and what the limitations are — so the examiner sees you can read science, not just memorise it.