The following glossary defines terms that are commonly encountered when studying zoology.
autotroph
An autotroph is an organism that obtains its carbon from carbon dioxide. Autotrophs need not feed on other organisms, since they can synthesize the carbon compounds they need for energy using sunlight and carbon dioxide.
deoxyribonucleic acid (DNA)
Deoxyribonucleic acid (DNA) is the genetic material of all living things (except viruses). Deoxyribonucleic acid (DNA) is a nucleic acid that occurs in most viruses, all bacteria, chloroplasts, mitochondria, and the nuclei of eucaryotic cells. DNA consists of a deoxyribose sugar in each nucleotide.
ecosystem
An ecosystem is a unit of the natural world that includes all the parts and interactions of the physical environment and the biological world.
ectothermy
Ectothermy is the ability of an organism maintain their body temperature by absorbing heat from their environment. They obtain heat either via conduction (by laying on warm rocks and absorbing the heat through direct contact, for example) or by radiant heat (by warming themselves in the sun).
Groups of animals that are ectothermic include reptiles, fishes, invertebrates, and amphibians.
There are some exceptions to this rule though, some organisms belonging to these groups do maintain their body temperature above that of the surrounding environment. Examples include mako sharks, some sea turtles and tuna.
An organism that employs ectothermy as a means of maintaining its body temperature is referred to as an ectotherm or is described as ectothermic. Ectothermic animals are also called cold-blooded animals.
endemic
An endemic organism is an organism that is restricted to, or native to, a specific geographical region and is not naturally found anywhere else.
environment
The environment consists of the surroundings of an organism, including the plants, animals, and microbes with which it interacts.
frugivore
A frugivore is an organism that relies on fruit as a sole source of food.
homeostasis
Homeostasis is the maintenance of constant internal conditions despite a varying external environment. Examples of homeostasis include the thickening of fur in winter, the darkening of skin in sunlight, the seeking of shade in heat, and the production of more red blood cells at high altitude are all examples of adaptations animals make in order to maintain homeostasis.
heterotroph
A heterotroph is an organism that is unable to obtain its carbon from carbon dioxide. Instead, heterotrophs obtain carbon by feeding on the organic material present in other organisms, living or dead.
All animals are heterotrophs. Blue whales feed on crustaceans. Lions eat mammals such as wildebeest, zebras and antelope. Atlantic puffins eat fish such as sandeel and herring. Green sea turtles eat seagrasses and algae. Many species of corals are nourished by zooxanthellae, tiny algae that live within the corals' tissues. In all of these cases, the animal's carbon comes from ingesting other organisms.
introduced species
An introduced species is a species that humans have placed into an ecosystem or community (either accidentally or intentionally) in which it does not naturally occur.
