Anamniotic is a term used in biology to refer to organisms that do not develop an amniotic membrane during their embryonic stage. The word's spelling can be explained through its IPA phonetic transcription: /ˌænæmniˈɑtɪk/. It starts with the prefix "ana-" meaning "without", followed by "mnio", which is derived from the Greek word "mneia" for "memory". The suffix "-otic" indicates a characteristic or condition. Therefore, "anamniotic" means lacking the ability to form a protective amniotic membrane in embryonic development.
Anamniotic is an adjective that refers to a specific biological characteristic or condition found in certain animals. The term is derived from the Greek words "an-", meaning without, and "amnion", which is the innermost membrane that develops around the embryo of a reptile, bird, or mammal.
In the field of biology, anamniotic is used to describe animals that lack an amnion during embryonic development. This includes various groups of animals such as fish and amphibians that undergo direct development, as well as reptiles and birds that lay eggs. These organisms are considered anamniotes because their embryos lack the protective membrane that surrounds and cushions the developing fetus in mammals, known as the amniotic sac.
In anamniotic organisms, the embryo develops directly in the external environment, without the need for the extra protective layer provided by the amnion. This is in contrast to amniotes, which include mammals and reptiles, where the amniotic sac plays a crucial role in providing a safe and regulated environment for the developing embryo. Anamniotes have different reproductive strategies and adaptations to compensate for the absence of the amniotic sac.
Overall, anamniotic is a term used to classify organisms that lack an amnion during embryonic development, highlighting an important anatomical and functional distinction in the animal kingdom.
Without an amnion, anamnionic.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "anamniotic" is derived from two Greek roots: "an-" meaning "without" and "amnion" referring to the thin, membrane-like structure that surrounds and protects the fetus of amniotes (reptiles, birds, and mammals) during development. The combination of these roots forms "anamniotic", which describes organisms that lack the amnion structure.