Gastrovascular
Having both a digestive and a circulatory function. Used especially to describe the body
cavity of a coelenterate.
Gastrovascular cavity
The central digestive compartment, usually with a single opening that functions as both
mouth and anus.
Gastrula
The two-layered, cup-shaped embryonic stage.
Gastrulation
The formation of a gastrula from a blastula.
Gated ion channel
A specific ion channel that opens and closes to allow the cell to alter its membrane
potential.

Principle

Any original inherent constituent which characterizes a substance, or gives it its essential
properties, and which can usually be separated by analysis; -- applied especially to drugs,
plant extracts, etc.
Gel electrophoresis
The separation of nucleic acids or proteins, on the basis of their size and electrical charge, by
measuring their rate of movement through an electrical field in a gel.
Gene
A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA
(or RNA, in some viruses).
Gene amplification
The selective synthesis of DNA, which results in multiple copies of a single gene, thereby
enhancing expression.
Gene cloning
The production of multiple copies of a gene.
Gene flow
The loss or gain of alleles from a population due to the emigration or immigration of fertile
individuals, or the transfer of gametes, between populations.