LACTIC ACID FERMENTATION: A form of anaerobic respiration that generates a byproduct called lactic acid. Lactic acid fermentation happens in human muscle cells when they run out of oxygen for cellular respiration. It's the burn you feel in your muscles during gym class.
LAW OF CONSERVATION OF MASS: Atoms are not created or destroyed in a chemical reaction. The total mass of the reactants should equal the total mass of the products.
LAW OF CROSSCUTTING: When a geologic feature (igneous intrusion or fault) cuts across another layer of rock, it is younger than the rock it cuts across / through.
LAW OF SUPERPOSITION: In undisturbed layers of rock, the oldest rocks are on the bottom. Each rock layer is younger than the rock layer below it, and older than the rock layer above it.
LEEUWENHOEK, Anton von: The first scientist to see sperm, red blood cells, and bacteria.
LEWIS DOT STRUCTURE: A representation of an atom that includes only the atom's symbol and dots to show the number of valence electrons
LICHEN: An organism formed from the symbiotic relationship (mutualism) between fungus and photosynthetic algae or bacteria. This is the green scale that grows on the side of trees.
LIMITING FACTOR: Any factor (biotic or abiotic) that limits the number and distribution of individuals of a species.
LIPIDS: A fat, oil, or wax. Lipids are large molecules, or polymers, made up of fatty acid monomers. Lipids are used for energy storage and insulation.
LOCOMOTION: Movement or travel
LYSOSOME: An organelle (cell part) responsible for digesting (breaking down) and sometimes recycling food and old cell parts. It's the garbage can of the cell!