microbiology
4 free lessons tagged microbiology across Science. Each one is a short sequence of focused steps with narration and a five-question quiz at the end — take them in any order, no signup required.
The unculturable majority: reading microbes we cannot grow
Most microbes on Earth have never been grown in a laboratory, so for a century microbiology studied the small fraction that cooperated. This lesson covers the great plate count anomaly, how 16S sequencing and metagenomics read organisms directly, and what those methods still cannot tell you.
Antibiotics: selective toxicity and how resistance defeats it
An antibiotic has to break something a bacterium has and you do not. This lesson covers the four target families, how MIC is measured, the four ways bacteria defeat a drug, and how a resistance gene moves between cells that are not even related.
How bacteria grow, and why counting them is hard
Bacterial growth is exponential, which makes the arithmetic simple and the intuition terrible. This lesson covers doubling time, the four phases of a culture, and the gap between the cells you can see down a microscope and the ones that will actually grow on a plate.
The bacterial cell: what makes it different
A bacterium and one of your cells are both alive and share almost no structure beyond that. This lesson walks the bacterial cell part by part, the wall, the loop of DNA, the smaller ribosome, and shows why each difference is exactly what an antibiotic aims at.