Biology
GCSE · OCR 21st Century,
Build your own quiz, flashcard deck, or exam paper from multiple subtopics.
15 cheat sheets
Microscopy & Magnification
Light and electron microscopes, magnification calculations, and unit conversions for GCSE Biology.
Animal & Plant Cells
Eukaryotic cell structures, organelle functions, and the key differences between animal and plant cells.
Human Impact on Ecosystems
Deforestation, global warming, pollution, and conservation strategies in GCSE Biology ecosystems.
Mitosis & the Cell Cycle
How one cell becomes two identical copies: chromosomes, the cell cycle, the four stages of mitosis, and why mitosis matters for growth, repair and reproduction.
Diffusion, Osmosis & Active Transport
Diffusion, osmosis and active transport - definitions, energy requirements, examples, and a comparison table of direction and what moves.
Enzymes
The lock-and-key model, denaturation, and how temperature, pH and substrate concentration affect rate of reaction.
The Immune System & Body Defences
Non-specific and specific defences, white blood cells, vaccination, and how the body fights pathogens.
Food Tests
Starch, reducing sugars, protein and lipid food tests with the reagents, positive results and safety tips.
Leaf Structure & Plant Tissues
Cross-section of a leaf with labelled layers, vascular tissue (xylem and phloem), meristem tissue, stomata, guard cells and their key functions.
Vaccination & Herd Immunity
How vaccines work, the primary vs secondary immune response, memory lymphocytes, herd immunity, and examples of common vaccines.
Photosynthesis
The photosynthesis equation, where it happens in the leaf, uses of glucose, and the four limiting factors with their rate graphs.
The Reflex Arc
Stimulus to response pathway through receptors, sensory and motor neurones, relay neurones, synapses and effectors.
Hormones & the Endocrine System
What the endocrine system is, the major glands and their hormones and effects, and how the nervous and endocrine systems compare.
Blood Glucose & Diabetes
How the pancreas regulates blood glucose via glucagon and insulin, negative feedback, and the causes and treatments of Type 1 and Type 2 diabetes.
Homeostasis
What homeostasis is, the negative feedback loop, receptors and effectors, and what gets controlled: body temperature, blood glucose, and water balance.
