Yeast cells – Cell biology
A yeast cell Yeast cells are a very common kind of eukaryote cell. They vary in size, but are usually about four thousandths of a millimeter (4 microns) in diameter, too [...]
A yeast cell Yeast cells are a very common kind of eukaryote cell. They vary in size, but are usually about four thousandths of a millimeter (4 microns) in diameter, too [...]
Vacuoles in an amoeba (a one-celled eukaryote) Vacuoles are little pockets in the cytoplasm of a cell where a cell stores food. You can see them with a good light [...]
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 [...]
Bacterium with a flagellum (under a microscope) Cells drift in the current... The simplest cells, developing about four billion years ago, had no way to control their own movement. They [...]
Krystie has Tay-Sachs disease Tay-Sachs is a disease where your lysosomes aren't working right. It's a disease you get in your DNA from your parents. Both your mother and your [...]
RNA molecule: A single strand of RNA, seen under an electron microscope The RNA molecule was probably one of the earliest steps towards life on Earth. RNA is short for [...]
A cell dividing into two cells The first reproduction One of the main ways we define whether something is alive is whether it can reproduce - if it can make a new [...]
Thermal proteins seen through a microscope Around four billion years ago, some of the amino acid molecules that were on the planet Earth began to join together into bigger molecules [...]
When the first amino acids came to Earth from space inside chunks of ice about five billion years ago, the ice melted on the hot Earth and turned to water, and the [...]
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 [...]