The Columbia Encyclopedia. Copyright © 2001-09 Columbia University Press. All rights reserved.
- trichina
Trichina, common name for species of roundworm of the phylum Nematoda. The species Trichinella spiralis is an important parasite, occurring in rats, pigs, and man, and is responsible for the d...
- hookworm
Hookworm, any of a number of bloodsucking nematodes in the phylum Nematoda, order Strongiloidae that live as parasites in humans and other mammals and attach themselves to the host's intestine...
- cloaca
Cloaca, in biology, enlarged posterior end of the digestive tract of some animals. The cloaca, from the Latin word for sewer, is a single chamber into which pass solid and liquid waste materia...
- pseudocoelomate
Pseudocoelomate, any of a group of invertebrates with a three-layered body that has a fluid-filled body cavity (pseudocoelom) between the endoderm and the mesoderm (the innermost and middle ti...
- aschelminths
Aschelminths, large assemblage of loosely related, wormlike organisms of extremely varied structure and habits. Formerly considered an animal phylum, these organisms are now more commonly refe...
- invertebrate
Invertebrate, any animal lacking a backbone. The invertebrates include the tunicates and lancelets of phylum Chordata, as well as all animal phyla other than Chordata. The major invertebrate p...
- pinworm
Pinworm, roundworm, Enterobius vermicularis, worldwide in distribution and the most common source of worm infestation of humans in the United States. Children are more commonly infested than a...
- Human Genome Project
Human Genome Project, international scientific effort to map all of the genes on the 23 pairs of human chromosomes and, to sequence the 3.1 billion DNA base pairs that make up the chromosomes ...
- worm
Worm, common name for various unrelated invertebrate animals with soft, often long and slender bodies. Members of the phylum Platyhelminthes, or the flatworms, are the most primitive; they are...
