Edexcel GCSE Biology Revision
GCSE Biology · Specification 1BI0 · England
Revising for Edexcel GCSE Biology? Below is every topic in the course, in specification order, with a short summary. Sign up free to get the full notes, quizzes, flashcards and exam questions for each one — filtered to the Edexcel course so you only revise what's on your exam.
Edexcel GCSE Biology topics
Topic 1 Key concepts in biology
All living organisms are made of cells, the basic structural and functional units of life. There are two main types: prokaryotic and eukaryotic. Prokaryotic cells are simple, lacking a true nucleus and membrane-bound organelles (e.g., bacteria). Eukaryotic cells are more complex, possessing a nucleus that contains genetic material and various organelles with specialised functions (e.g., animal, plant, fungal, algal cells). Understanding cell structure is fundamental to biology.
Topic 2 Cells and control
Cells are the basic building blocks of all living organisms. There are two main types: eukaryotic and prokaryotic. Eukaryotic cells, found in animals, plants, fungi, and protists, are complex, typically larger, and have a nucleus containing genetic material, along with other membrane-bound organelles like mitochondria and chloroplasts (in plants). Prokaryotic cells, found in bacteria and archaea, are much simpler, smaller, and lack a nucleus and most other membrane-bound organelles. Their genetic material floats freely in the cytoplasm.
Topic 3 Genetics
Your body is made of billions of cells, and inside almost every cell is a nucleus containing chromosomes. Chromosomes are long strands of DNA, tightly coiled up. DNA (deoxyribonucleic acid) is the genetic material that carries all the instructions for making an organism. A gene is a short section of DNA that codes for a specific protein, which in turn determines a particular characteristic or trait, like eye colour. Humans have 23 pairs of chromosomes, with one set inherited from each parent.
Topic 4 Natural selection and genetic modification
Organisms within a species show variation in their characteristics due to differences in their genes. Some of these variations make individuals better adapted to their environment. For example, a fast gazelle is better at escaping predators. If environmental conditions change, individuals with advantageous characteristics are more likely to survive, reproduce, and pass on these beneficial alleles to their offspring. This process, known as natural selection, leads to a gradual increase in the frequency of beneficial alleles in a population over time, causing evolution.
Topic 5 Health, disease and the development of medicines
Health is defined as a state of complete physical, mental, and social well-being, not merely the absence of disease or infirmity. Disease, on the other hand, is a condition that impairs normal functioning and is typically manifested by distinguishing signs and symptoms. Diseases can be communicable (infectious), caused by pathogens and transferable between individuals, or non-communicable (non-infectious), such as genetic disorders or conditions influenced by lifestyle factors like diet and exercise. Many factors, including diet, stress, and life situations, can impact health, sometimes making individuals more susceptible to diseases.
Topic 6 Plant structures and their functions
Plants are multicellular organisms with organised structures, just like animals. They have different organ systems working together. The root system is typically underground, anchoring the plant and absorbing water and mineral ions. The shoot system is usually above ground, consisting of the stem, leaves, and reproductive structures like flowers. The stem supports the plant and transports substances, while leaves are the primary sites for photosynthesis. Each system has specialised functions vital for the plant's survival and growth.
Topic 7 Animal coordination, control and homeostasis
The nervous system is a complex network of specialised cells called neurones that transmit electrical signals (nerve impulses) throughout the body. It allows organisms to detect stimuli, process information, and respond rapidly. It's broadly divided into the central nervous system (CNS), comprising the brain and spinal cord, and the peripheral nervous system (PNS), which includes all other nerves. The nervous system coordinates actions and allows communication between different parts of the body, enabling functions like movement, thought, and sensation.
Topic 8 Exchange and transport in animals
The human circulatory system is a double circulatory system, meaning blood passes through the heart twice for each complete circuit of the body. It consists of the heart, blood vessels (arteries, veins, capillaries), and blood. The right side of the heart pumps deoxygenated blood to the lungs, while the left side pumps oxygenated blood to the rest of the body. This efficient system ensures that oxygen and nutrients are delivered quickly and waste products are removed effectively from cells throughout the body.
Topic 9 Ecosystems and material cycles
An ecosystem consists of all the living organisms (biotic factors) and the non-living components (abiotic factors) interacting within a specific area. Biotic factors include producers, consumers, and decomposers, while abiotic factors are elements like temperature, light intensity, water availability, and pH. All organisms in an ecosystem are interdependent; a change in one population or abiotic factor can have significant impacts throughout the entire system. This interdependence creates complex food webs and ensures the cycling of materials essential for life, maintaining ecosystem balance.
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