nematode

(noun)

A small invertebrate animal of the phylum Nematoda.

Related Terms

Examples of nematode in the following topics:

  • Nematodes

    • Nematodes, or roundworms, are the most diverse phylum of pseudocoelomates and one of the most diverse animal phyla.
    • Nematodes are characterized by the presence of a tubular digestive system with openings at both ends.
    • Nematodes are also capable of exhibiting parasitic behavior that contribute to digestive system diseases.
    • Enterobius, referred to as pinworm, is a type of parasitic nematode that is commonly found in the intestine of children.
    • Compare and contrast mechanisms of infection for the parasitic nematodes: Ascaris lumbricoides and Enterobius

  • Phylum Nematoda

    • Nematodes are present in all habitats.
    • In contrast with cnidarians, nematodes show a tubular morphology and circular cross-section.
    • In nematodes, specialized excretory systems are not well developed.
    • Scanning electron micrograph of soybean cyst nematode and its egg.
    • Nematodes are cylindrical in shape, often looking like thin hairs.

  • Characteristics of Helminths

    • The parasitic intestinal helminths can be divided into three groups which include Nematodes (roundworms), Cestodes (tapeworms), and Trematodes (flukes).
    • It should be noted, however, that blood and tissue roundworms (Nematodes) exist that will not be discussed in this section.
    • The three commonly studied and well-known groups include the intestinal Nematodes (round worms), tapeworms (Cestodes), and blood, tissue and organ flukes (Trematodes).
    • This summary does not contain an exhaustive compilation of all human parasitic nematodes, but merely a representation of several species.

  • Classification and Identification of Helminths

    • Nematodes are characterized by a cylindrical body shape and do indeed have a body cavity.
    • The sex of nematodes is dioecious (distinct male and female organisms).

  • Gene Expression for Spatial Positioning

    • Scientists study organogenesis extensively in the lab in fruit flies (Drosophila) and the nematode Caenorhabditis elegans.
    • The nematode C.elegans has roughly 1000 somatic cells and scientists have studied the fate of each of these cells during their development in the nematode life cycle.

  • Helminths

    • Poorly washed vegetables eaten raw may contain eggs of nematodes such as Ascaris, Enterobius, Thichuris, and or cestodes such as Taenia, Hymenolepis, and Echinococcus.
    • Schistosomes and nematodes such as hookworms (Ancylostoma an Necator) and Strongyloides can penetrate the skin.

  • Signaling in Yeast

    • Comparisons of the genomes of yeasts, nematode worms, fruit flies, and humans illustrate the evolution of increasingly-complex signaling systems that allow for the efficient inner workings that keep humans and other complex life forms functioning correctly.
    • More complex organisms such as nematode worms and fruit flies have 454 and 239 kinases, respectively.

  • Superphylum Ecdysozoa

    • The superphylum Ecdysozoa includes the nematode worms and the arthropods, both of which have a tough external covering called a cuticle.

  • Verrucomicrobia

    • A number of as-yet uncultivated species have been identified in association with eukaryotic hosts including extrusive explosive ectosymbionts of protists and endosymbionts of nematodes residing in their gametes.

  • Plant Defenses Against Pathogens

    • These infectious microorganisms, such as fungi, bacteria, and nematodes, live off of the plant and damage its tissues.