Ecological species concept
A concept of species, according to which a species is a set of organisms adapted to a particular, discrete set of resources (or "niche") in the environment. Compare with biological species concept, cladistic species concept, phenetic species concept, and recognition species concept.

Ecosystem
A community of organisms interacting with a particular environment

EDC
Estimated date of confinement. Also known as EDD; estimated date of delivery. The expected delivery date of a pregnancy.

Effector molecule
A small molecule that regulates the activity of as a repressor protein) by binding to a receptor site on the protein.

Electrophoresis
A method of separating large molecules (such as DNA fragments or proteins) from a mixture of similar molecules. An electric current is passed through a medium containing the mixture, and each kind of molecule travels through the medium at a different rate, depending on its electrical charge and size. Agarose and acrylamide gels are the media commonly used for electrophoresis of proteins and nucleic acids
2. In molecular biology, a method of separating large molecules such as DNA fragments or proteins from a mixture of similar molecules.
3. A technique used to separate macromolecules by their differential migration through a semi-solid matrix in an electrical field.
4. The method of distinguishing entities according to their motility in an electric field. In evolutionary biology, it has been mainly used to distinguish different forms of proteins. The electrophoretic motility of a molecule is influenced by its size and electric charge