Biology Triple Science Revision Overview

This is your complete revision tracker for Biology Triple Science Higher tier. The guide covers both Paper 1 and 2 content that you'll face in your exams.

The booklet uses a simple RAG system (Red, Amber, Green) to help you track your understanding of each topic. You can revisit topics multiple times and see your progress improve from your first attempt through to your fifth review.

Quick Tip: Use this as your go-to checklist - tick off topics as you master them and focus extra time on any areas marked red or amber.

Cell Biology - What You Need to Know

Cell Biology forms the foundation of everything else in biology. You'll need to understand different types of cells - from basic animal and plant cells to more complex bacterial cells and how they specialise for different jobs.

The microscopy sections are crucial for your practicals. Make sure you can calculate magnification, understand standard form, and know the proper techniques for culturing microorganisms safely.

Cell division through mitosis and the role of stem cells are key exam topics. Don't forget the transport methods - diffusion, osmosis, and active transport - as these concepts appear throughout biology.

Exam Focus: Cell specialisation examples and transport calculations are popular exam questions, so practise these until they're second nature.

Organisation - From Cells to Organ Systems

This section shows how biology builds up from cells to tissues to organs and finally complete organ systems. It's all about understanding how structure relates to function.

Enzymes are absolutely vital - they speed up reactions in your body and have specific conditions where they work best. You'll need to know how temperature and pH affect enzyme activity, plus the key digestive enzymes and what they break down.

The circulatory system includes your heart, blood vessels, and blood itself. Focus on the differences between arteries, veins, and capillaries, and understand how the heart pumps blood around your body efficiently.

Remember: Enzyme graphs showing optimum conditions are exam favourites - practise interpreting and drawing these.

Health and Disease

Non-communicable diseases don't spread between people but can seriously affect health. Learn the key risk factors for heart disease and cancer, including lifestyle choices like smoking and poor diet.

Understanding how to treat heart disease through medication, surgery, or lifestyle changes shows the link between biology and real-world medicine. Cancer occurs when cell division goes wrong and cells multiply uncontrollably.

Plant tissues and organs work differently from animals. Transpiration moves water through plants, while translocation transports sugars. Stomata control gas exchange and water loss - crucial for plant survival.

Real-world Link: Many exam questions connect risk factors to actual health outcomes, so think about cause and effect relationships.

Infection and Response

Communicable diseases spread from person to person through pathogens like bacteria, viruses, fungi, and protists. Your body has amazing defence systems including white blood cells and antibodies to fight infections.

Antibiotics kill bacteria but don't work against viruses - this is why you can't cure a cold with antibiotics. Drug development takes years of testing to ensure medicines are safe and effective.

Monoclonal antibodies are identical antibodies that can target specific cells, making them useful for treating diseases and pregnancy tests. Plants also get diseases and have their own defence mechanisms.

Common Mistake: Remember that antibiotics only work against bacterial infections, not viral ones like flu or COVID-19.

Bioenergetics - Energy in Living Things

Photosynthesis is how plants make glucose using light energy, carbon dioxide, and water. The glucose can be used immediately for energy or stored as starch for later use.

You'll need to know the photosynthesis equation and understand how factors like light intensity, temperature, and carbon dioxide concentration can limit the rate of photosynthesis.

Respiration releases energy from glucose in all living cells. During exercise, your body needs more energy, so your breathing and heart rate increase to deliver more oxygen to your muscles.

Practical Skills: Photosynthesis experiments using pond weed and measuring oxygen production are common practical questions.

Homeostasis and Response

Homeostasis keeps your internal conditions stable despite changes in your environment. Your body constantly monitors and adjusts things like temperature, blood sugar, and water levels.

The nervous system includes your brain, spinal cord, and nerves. Synapses are gaps between nerve cells where chemical messages pass across. Reflex actions protect you from danger by bypassing your brain for super-fast responses.

Your endocrine system uses hormones to control processes like growth, reproduction, and blood glucose levels. Diabetes occurs when blood sugar control goes wrong, requiring careful management through diet or insulin.

Key Concept: Negative feedback loops are crucial for homeostasis - when something increases, the body responds to decrease it, and vice versa.

Hormones and Control Systems

The endocrine system works more slowly than the nervous system but has longer-lasting effects. Hormones like insulin control blood glucose, while others manage water balance in your kidneys.

Reproductive hormones control puberty, the menstrual cycle, and fertility. Various methods of contraception work by interfering with these natural hormone cycles.

Plant hormones like auxins control growth responses to light and gravity. This explains why plants grow towards light sources and why roots grow downwards into soil.

Exam Tip: Hormone graphs showing levels during the menstrual cycle are frequently tested - make sure you can interpret and label these accurately.

Inheritance, Variation and Evolution

DNA contains the genetic code that determines your characteristics. Protein synthesis uses this code to make the proteins your body needs. Understanding genetic inheritance helps predict what traits offspring might have.

Genetic crosses show how characteristics pass from parents to children. Some inherited disorders like cystic fibrosis are caused by faulty genes, which genetic screening can detect.

Selective breeding allows humans to choose which animals or plants reproduce, developing useful characteristics over time. Genetic engineering and cloning are modern techniques that can modify organisms directly.

Calculation Focus: Genetic cross diagrams and probability calculations appear frequently in exams - practise Punnett squares until they're automatic.

Evolution and Ecology

Natural selection drives evolution - organisms with advantageous characteristics are more likely to survive and reproduce. Over time, this can lead to speciation where new species develop.

Classification organises living things into groups based on their similarities and evolutionary relationships. Modern classification uses DNA evidence alongside physical characteristics.

Ecology studies how organisms interact with each other and their environment. Food webs, population dynamics, and environmental change all affect ecosystem balance. The cycling of materials like carbon and nitrogen keeps ecosystems functioning.

Environmental Focus: Climate change and human impact on ecosystems are increasingly important exam topics - understand both the problems and potential solutions.