Explore structured biology courses, solved problems, simulations and Python activities.
What blood is made of and what each kind of cell does. Why the blood group matters in a transfusion, and what the Rh factor means for a baby. How a clot forms, and how the lymph returns tissue fluid to the blood.
How animals move their blood: open and closed circulation, and the hearts of fish, frogs and mammals. The chambers, valves and nodal tissue of the human heart, and the two loops of the double circulation.
What the heart does in one beat, and how much blood it pumps in a minute. How the electrical signal of the heart is drawn as an ECG, how nerves and hormones change the heart rate, and what goes wrong in high blood pressure and heart disease.
How do a sponge, an earthworm, a fish and a human breathe? Here you learn the parts of the human respiratory system, the movements of the chest that pull air in and push it out, and the volumes of air that a spirometer measures.
Why does oxygen move into the blood and carbon dioxide move out? You learn about partial pressure, the thin membrane of the alveolus, the part that haemoglobin plays in carrying oxygen, and how to read the oxygen dissociation curve.
How does carbon dioxide travel back from the tissues? You follow the bicarbonate pathway and the chloride shift. You find the centres in the brain that set the rhythm of breathing. You also learn what goes wrong in asthma, emphysema and the dust diseases of workers.
How a plant grows and how fast. The three phases of growth, arithmetic and geometric growth, absolute and relative growth rate, and the conditions growth needs. Then differentiation, dedifferentiation, redifferentiation, development and plasticity.
The five chemical messengers of a plant: auxins, gibberellins, cytokinins, ethylene and abscisic acid. What each one does, the experiments that found them, and how they work together.
Why a seed can wait for years, how a plant knows the length of the night, and why some plants need a cold winter before they flower. With the classic experiments and how to read them.
Do plants breathe? How a cell turns food into ATP, and how glucose is split into pyruvic acid in glycolysis. What a cell does with pyruvic acid when there is no oxygen: alcoholic and lactic acid fermentation.
What happens to pyruvic acid when oxygen is present. The link reaction and the Krebs cycle in the matrix of the mitochondrion, then the electron transport system and the making of ATP on the inner membrane.
How much ATP one glucose molecule earns, and why the figure in a book is never exact. How fats and proteins enter the pathway and how the pathway builds new molecules. The respiratory quotient and what it tells about the substrate.
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Beyond the textbook: reading spirometer graphs of healthy and diseased lungs, working out ventilation and dead space, calculating partial pressures and the oxygen carried by blood, and reasoning about every shift of the dissociation curve. Twelve harder problems and a full timed mock exam.
Beyond the textbook: a full account of the ATP, NADPH, carbon and photons that photosynthesis spends, a point-by-point comparison of the C3 and C4 pathways, and the reading of limiting-factor graphs and classic experiments. Twelve harder problems and a full timed mock exam.
Beyond the textbook: how proteins fold and why shape means function, and Michaelis-Menten kinetics with the Lineweaver-Burk plot. Then competitive and non-competitive inhibition by numbers, and how pathways are controlled by feedback, with a full timed paper.
The plant groups side by side, with their key examples, economic uses and the tricky points that exams test, worked step by step, and a full NEET-style mock exam.
Two kinds of bacteria can differ from each other as much as a bacterium differs from you. How do biologists know? In this course we read three ideas that the main chapter only touches: the three domains of life, how bacteria are stained, grown and counted in a laboratory, and how a virus takes over a cell. Then we solve harder problems at the level of NEET, AP Biology and A-Level Biology, and take a timed test.
A horse and a donkey can have a young one, the mule, and the mule cannot have young. So are the horse and the donkey one species or two? In this course we read three ideas that the main chapter only touches: what a species really is, the finer rules that give each species one name, and how a key and a DNA barcode find a name. Then we solve harder problems at the level of NEET, AP Biology and A-Level Biology, and take a timed test.