OCR As Level Biology A Paper 1 2025 Mark Scheme

Get the official OCR AS Level Biology A H020/01 Breadth in Biology mark scheme from the June 2025 examination series. This examiner-approved PDF contains the exact mark allocations, indicative scientific points, practical-skills guidance, calculation methods, examiner annotations, and assessment-objective breakdowns used by OCR examiners during live Summer 2025 marking.

This mark scheme provides detailed examiner guidance for questions covering membrane structure, ATP, microscopy, stem cells, colorimetry, oxygen dissociation curves, the Bohr effect, immunity, biodiversity, meiosis, DNA replication, plasma cells, B lymphocytes, phloem loading, membrane permeability, transport systems, ECG interpretation, and stem cell applications. It includes accepted alternative answers, calculation tolerances, statistical-analysis guidance, annotation conventions, and practical-method expectations used by OCR examiners. Pair it with the matching OCR H020/01 June 2025 question paper on markscheme.net for complete examiner-style revision and exam preparation. Updated for the 2025/2026 academic year, mobile-friendly, and instantly downloadable from markscheme.net.

This document is designed for OCR AS Level Biology A students preparing for the 2026 examination series, Year 12 learners studying Breadth in Biology, retake students targeting A/A grades, and home-schooled candidates seeking examiner-level insight into OCR marking expectations.

It is also essential for teachers, private tutors, revision-course providers, and parents supporting Biology revision at home. The mark scheme can be used for mock-exam grading, practical-skills assessment, data-analysis evaluation, exam-technique improvement, and identifying weaknesses in OCR AS Biology responses.