G
gall bladder
A small pear-shaped organ, connected to the liver and the digestive tract, which store bile, a digestive juice
gene [jeen]
The portion of the DNA or genetic material that gives instructions for a living organism to make one protein. Each human has 70,000 pairs of genes. They provide the information that allows cells to synthesize the specific proteins needed for function.
Genetics [gee net iks]
The branch of biology that deals with genes, heredity and variation between organisms.
glacier [glay shur]
A large area of ice that receives more snow in winter than melts in summer. Glaciers are usually found in mountain valleys or at the earth's poles. Glaciers move slowly downhill under their own massive weight.
glucose [glu kos]
A simple sugar which is the main source of energy for the living organisms.
GPS = global positioning system
A worldwide navigation system that uses information from satellites.