Human organs: medieval science
Chinese drawing of the human organs (about 1200) Eyes and fevers Between the Middle Ages and modern times, doctors have learned a lot of new things about how human bodies [...]
Chinese drawing of the human organs (about 1200) Eyes and fevers Between the Middle Ages and modern times, doctors have learned a lot of new things about how human bodies [...]
Two and a half billion years ago, the Archaean Eon ended and the Proterozoic Eon began. Trillions of prokaryote cells lived in Earth's oceans. Some of these cells could photosynthesize their energy [...]
Human sperm cells with flagella (under a microscope): Eukaryote flagella Not the old kind of flagella About two billion years ago, the first eukaryote cells evolved from the earlier prokaryote [...]
A prokaryote (seen through a microscope) What does "prokaryote" mean? The simplest living cells are called prokaryotes, which is Greek for "before the nucleus" - these are cells that were [...]
A eukaryote cell (seen through a microscope) full of chloroplasts How do eukaryotes divide? Eukaryote cells generally reproduce themselves using a method called mitosis. When a eukaryote cell senses that there [...]
A mitochondrion (seen through a microscope) When did mitochondria evolve? About two billion years ago, in the Proterozoic, there were only prokaryotic cells on Earth. Mitochondria probably started out as [...]
Cell waste: A cell with a vacuole Cell waste and vacuoles Soon after eukaryote cells began to make vacuoles to help them catch their food and store it, about 600 [...]
A man who has ALS If your mitochondria are not working right, or you have too few mitochondria, you can easily see the results. Your body won't work right, especially [...]
Taken with an electron microscope at the University of Melbourne, Australia Here's an active game where you can act out what a Golgi body does. Form into groups of eight, [...]
Amoeba - a one-celled organism - Cell digestion How do cells get energy? All cells have to have some way to get energy from outside themselves, or they will starve [...]