Gastro-
Stomach (gastric)
Gen-
Produce, begin (antigen)
Genesis
Forming, creating (morphogenesis)
Geo-
Earth (Geology)
Gig-
Giant (Gigabyte)
Glomus-
A ball (glomerulus)
Glot-, gloss
Tounge (glossary)
Glycys-
Sweet (glycogen)
Gno-, gni-
Know (agnostic)
Granum
Grain, seed (granular)
Graph
Write (geography)
Gravi-
Weight (gravity)
Gregar
Group (segregation)
Gym
Naked (gymnosperm)
Gyn
Female (gynecology)