Glossary | G

Gamete
mature sperm or egg, capable of fusing during fertilization
Gametophyte
gamete-forming phase in alteration of plant generations
Gastropod
mollusks of the class Gastropoda, such as snails, slugs, cowries, or limpets, characteristically having a single, usually coiled shell or no shell at all, a ventral muscular foot for locomotion, and eyes and feelers located on a distinct head
Generic
relating to or determined by the origin, development, or causal antecedents of something
Genus
subdivision of a biological family: biological ranking between family and species
Gestation
period during which young are carried in the uterus
Gill
aquatic respiratory organ
Gill net
a fishing net set vertically in the water so that fish swimming into it are entangled by the gills in its mesh
Gill raker
modified dermal denticles that are projections on the inner margin of the gill arches that point forward and upward and act as a sieve by straining water preventing food particles from entering the gills
GIS
Geographic Information System: a system of hardware and software used for storage, retrieval, mapping, and analysis of geographic data.
Gonads
male and female reproductive organs
Gonopore
opening through which eggs or sperm are released, especially in invertebrates
Gravid
pregnant; bearing eggs or young
Grazers
animals that eat growing herbage, attached algae, or phytoplankton as their principle source of energy
Gregarious
tend to live in groups; social