Perfect Let’s go through OCR A-level Biology Module 2 in a clear and structured
way.
OCR A-Level Biology
Module 2 – Foundations in Biology
Overview
Module 2 is the core biological knowledge that underpins the rest of the course. It
covers the fundamental biological principles, techniques, and structures that you’ll
need for later modules like cell division, biochemistry, genetics, and ecosystems.
Key Topics in Module 2
1. Microscopy
• Types of microscopes:
o Light microscope – up to ×1500 magnification, resolution 200 nm.
o Transmission Electron Microscope (TEM) – very high resolution (~0.1
nm), 2D images.
o Scanning Electron Microscope (SEM) – 3D images, lower resolution
than TEM (~10 nm).
• Staining:
o Dyes (e.g. methylene blue, iodine) increase contrast.
o Differential staining helps identify different cell structures (e.g. Gram
staining bacteria).
• Preparation:
o Smear, squash, and sectioning techniques.
• Calculations:
o Magnification = Image size ÷ Actual size
o Converting units (mm ↔ μm ↔ nm).
2. Cell Structure
