A subphylum of chordates intermediate between the invertebrates and the true vertebrates. It includes the LANCELETS. Its members are characterized by a NOTOCHORD which extends into the adult stage head.
A portion of the animal phylum Chordata comprised of the subphyla CEPHALOCHORDATA; UROCHORDATA, and HYPEROTRETI, but not including the Vertebrata (VERTEBRATES). It includes nonvertebrate animals having a NOTOCHORD during some developmental stage.
Phylum in the domain Eukarya, comprised of animals either with fully developed backbones (VERTEBRATES), or those with notochords only during some developmental stage (CHORDATA, NONVERTEBRATE).
A subphylum of chordates intermediate between the invertebrates and the true vertebrates. It includes the Ascidians.
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
The only species of a cosmopolitan ascidian.
The relationships of groups of organisms as reflected by their genetic makeup.
A phylum of the most familiar marine invertebrates. Its class Stelleroidea contains two subclasses, the Asteroidea (the STARFISH or sea stars) and the Ophiuroidea (the brittle stars, also called basket stars and serpent stars). There are 1500 described species of STARFISH found throughout the world. The second class, Echinoidea, contains about 950 species of SEA URCHINS, heart urchins, and sand dollars. A third class, Holothuroidea, comprises about 900 echinoderms known as SEA CUCUMBERS. Echinoderms are used extensively in biological research. (From Barnes, Invertebrate Zoology, 5th ed, pp773-826)
The system of glands that release their secretions (hormones) directly into the circulatory system. In addition to the ENDOCRINE GLANDS, included are the CHROMAFFIN SYSTEM and the NEUROSECRETORY SYSTEMS.
Ductless glands that secrete HORMONES directly into the BLOOD CIRCULATION. These hormones influence the METABOLISM and other functions of cells in the body.
Pathological processes of the ENDOCRINE GLANDS, and diseases resulting from abnormal level of available HORMONES.
Exogenous agents, synthetic and naturally occurring, which are capable of disrupting the functions of the ENDOCRINE SYSTEM including the maintenance of HOMEOSTASIS and the regulation of developmental processes. Endocrine disruptors are compounds that can mimic HORMONES, or enhance or block the binding of hormones to their receptors, or otherwise lead to activating or inhibiting the endocrine signaling pathways and hormone metabolism.
Tumors or cancer of the ENDOCRINE GLANDS.
Chemical substances having a specific regulatory effect on the activity of a certain organ or organs. The term was originally applied to substances secreted by various ENDOCRINE GLANDS and transported in the bloodstream to the target organs. It is sometimes extended to include those substances that are not produced by the endocrine glands but that have similar effects.
A branch of biology dealing with the structure of organisms.
The study of animals - their morphology, growth, distribution, classification, and behavior.
Instinctual behavior pattern in which food is obtained by killing and consuming other species.
A muscular organ in the mouth that is covered with pink tissue called mucosa, tiny bumps called papillae, and thousands of taste buds. The tongue is anchored to the mouth and is vital for chewing, swallowing, and for speech.
Bony structure of the mouth that holds the teeth. It consists of the MANDIBLE and the MAXILLA.
Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.
Tumors or cancer of the TONGUE.
The oval-shaped oral cavity located at the apex of the digestive tract and consisting of two parts: the vestibule and the oral cavity proper.
It is a form of protection provided by law. In the United States this protection is granted to authors of original works of authorship, including literary, dramatic, musical, artistic, and certain other intellectual works. This protection is available to both published and unpublished works. (from Circular of the United States Copyright Office, 6/30/2008)
Protective measures against unauthorized access to or interference with computer operating systems, telecommunications, or data structures, especially the modification, deletion, destruction, or release of data in computers. It includes methods of forestalling interference by computer viruses or so-called computer hackers aiming to compromise stored data.
The privacy of information and its protection against unauthorized disclosure.
The state of being free from intrusion or disturbance in one's private life or affairs. (Random House Unabridged Dictionary, 2d ed, 1993)
A phylum of radially symmetrical invertebrates characterized by possession of stinging cells called nematocysts. It includes the classes ANTHOZOA; CUBOZOA; HYDROZOA, and SCYPHOZOA. Members carry CNIDARIAN VENOMS.
A plant family of the order ROSALES, subclass Rosidae, class Magnoliopsida.
Animals that have no spinal column.