A Level Biology

Cell Structure & Biological Molecules

The building blocks of life. Work explores the ultrastructure of prokaryotic and eukaryotic cells seen through light and electron microscopes, the calculation of magnification and actual size, and the carbohydrates, lipids, proteins and water common to all cells — how their structures determine their roles, and the food tests used to detect them.

Enzymes, Membranes & the Cell Cycle

How cells work and multiply. Work explores enzymes as globular protein catalysts, the factors and inhibitors that alter their rate, the fluid mosaic membrane and the movement of substances across it by diffusion, osmosis and active transport — before the mitotic cell cycle, chromosome behaviour, telomeres and stem cells.

The code, and the plumbing. Work explores the structure of DNA and RNA, semi-conservative replication, and how the base sequence of a gene becomes a polypeptide through transcription and translation — then the xylem, phloem and mammalian circulatory system that move water, assimilates and oxygen around the body.

Life on the front line. Work explores the structure and function of the human gas exchange system, the biology and transmission of cholera, malaria, tuberculosis and HIV/AIDS, the use and misuse of antibiotics, and how the immune system — phagocytes, lymphocytes, antibodies and vaccination — defends the body against disease.

Biology at the bench, and on paper. The eleven AS topics revisited, practical skills for Paper 3 sharpened — accurate observation, drawing from slides, handling and evaluating data — and past papers worked through before students sit Papers 1, 2 and 3.

Straight into A2. After the AS exams, work begins on ATP as the universal energy currency, the stages of aerobic and anaerobic respiration, respiratory quotients, and the adaptations of organisms to environments where oxygen is scarce.

Photosynthesis

Life depends on the continuous transfer of energy. Work explores how chloroplast structure suits its function, the light-dependent and light-independent stages, chromatography of photosynthetic pigments, and how light intensity, carbon dioxide concentration and temperature limit the rate — investigated practically using redox indicators.

Keeping conditions steady. Work explores negative feedback, the regulation of blood glucose and the kidney’s role in osmoregulation, the structure and function of neurones, the action potential and synaptic transmission, muscle contraction, the control of the stomatal aperture in plants — and the role of hormones and plant growth regulators.

Evolution, in full. Work explores meiosis and the origins of genetic variation, monohybrid and dihybrid inheritance and the chi-squared test, the control of gene expression, then how natural selection, genetic drift and the Hardy–Weinberg principle change allele frequencies — and how isolation gives rise to new species.

Cataloguing and controlling life. Work explores the three-domain system and species concepts, ecosystems, sampling and Simpson’s index of diversity, the case for conservation — before the tools of genetic technology: PCR, gel electrophoresis, recombinant DNA and gene editing, and their applications in medicine and agriculture.

The final stretch. Revision is active: the A Level topics revisited, the planning, analysis and evaluation skills of Paper 5 sharpened, structured-answer technique practised, and past papers worked through before students sit Papers 4 and 5 — turning two years of biology into confident, exam-ready understanding.