IGCSE Biology 0610 notes, quizzes & practice

The seven life processes every living organism shows, how biologists sort millions of species into groups using shared features, how to write and use a dichotomous key, and where viruses fit — plus the vertebrate classes, arthropod groups and the five kingdoms you must be able to list.

What plant, animal and bacterial cells share and what sets them apart, what every cell part actually does, how cells specialise into ciliated cells, root hairs, neurones and red blood cells, how cells build tissues, organs and organ systems, and how to turn a drawing length into a real size with the magnification equation.

How every substance that enters or leaves a cell gets there: diffusion down concentration gradients, osmosis of water through partially permeable membranes (and what turgor, wilting and plasmolysis really are), and active transport — the energy-hungry uphill route used by root hair cells.

The molecules every cell is built from and runs on — carbohydrates, fats, proteins and DNA — how to test for each one with the classic food tests, and how enzymes speed up every reaction in your body with active sites, temperature curves and pH optima.

How plants feed themselves: the photosynthesis equations, what happens to the glucose a leaf makes, why nitrates and magnesium matter, how light, carbon dioxide and temperature limit the rate, and how every layer of a leaf is adapted to catch light and exchange gases.

What a balanced diet really contains, the journey food takes from mouth to colon, how teeth and muscle churn food physically, how amylase, protease and lipase digest it chemically, and how villi soak up the products — plus the deficiency diseases and the role of bile.

Two systems, one plant: xylem hauling water from root hair to leaf on the transpiration pull, and phloem moving sucrose from sources to sinks — plus the potometer experiment, the factors that change transpiration rate, and why a plant wilts.

The mammalian double circulation in full: why the heart has two sides, how valves keep blood one-way, what the ECG and pulse reveal, why coronary arteries matter, how vessel structure matches pressure, and how plasma, red cells, white cells and platelets divide the work — with clotting to finish.

How pathogens spread, how skin, mucus, stomach acid and white cells hold the line, why clean water and sewage treatment matter, and how active immunity, vaccination, memory cells and passive immunity from the placenta and breast milk defend the body — with cholera as the worked-through case study.

The full journey from air to ATP: the breathing system and its alveolar exchange surfaces, how ribs, intercostal muscles and the diaphragm ventilate the lungs, what limewater reveals about inspired and expired air, the aerobic and anaerobic respiration equations, yeast at different temperatures, and how the oxygen debt is repaid.

How the body gets rid of its waste: carbon dioxide out through the lungs, urea made by deamination in the liver and excreted by the kidneys with excess water and ions, the urinary system labelled from kidney to urethra, and the nephron’s filter-and-reclaim routine that turns blood filtrate into urine.

The body’s two control systems and how they are kept in balance: electrical reflex arcs and synapses, the eye from cornea to cones, hormones from adrenaline to insulin, negative-feedback homeostasis of glucose and temperature, auxin’s control of shoot growth — and how antibiotics fight bacteria while resistance breeds.

Making new organisms: identical offspring from one parent versus genetically different offspring from fused gametes, insect- and wind-pollinated flowers with pollen-tube fertilisation, the human male and female systems, sperm and egg adaptations, the placenta’s exchange role, puberty, the menstrual cycle’s hormone control, and how STIs such as HIV spread and are controlled.

How genetic information passes from generation to generation: chromosomes, genes and alleles; haploid gametes from meiosis and identical cells from mitosis; monohybrid crosses worked through Punnett squares to 3:1 and 1:1 ratios; test crosses for unknown genotypes; codominance and the ABO blood groups; and red-green colour blindness as sex linkage.

Where differences come from and what does the sorting: continuous and discontinuous variation, mutations stirred up by ionising radiation, the adaptive features of xerophytes and hydrophytes, natural selection spelled out from variation to passing on alleles, antibiotic resistance as evolution in real time, and selective breeding by human choice.

Ecology end to end: energy from the Sun flowing through food chains and pyramids, producers, consumers and decomposers, the carbon and nitrogen cycles, sigmoid population growth, and the human footprint — monocultures, deforestation, sewage and fertiliser eutrophication, plastics and greenhouse gases — closing with sustainable conservation of forests, fish stocks and endangered species.

Biology as industry: why bacteria are the perfect workforce, yeast’s anaerobic respiration in bread and biofuels, pectinase clearing juice, enzymes in washing powders, lactase for lactose-free milk, fermenters growing insulin and penicillin under controlled conditions, and how restriction enzymes, sticky ends and recombinant plasmids build GM bacteria and GM crops.