Parasitism Sentence Examples
The various degrees of parasitism are to a certain extent explained by the foregoing.
A flea living off of a dog's body is an example of parasitism.
Parasitism occurs when one organism makes another organism its home and source of life.
Parasitism is almost always harmful to the host organism.
Commensalism occurs in a few instances, but parasitism either external or internal is rare.Advertisement
With parasitism, only one of the organisms involved is benefiting from the relationship.
I give my pets vaccinations and preventive medication to avoid various types of parasitism.
There can be little doubt that in some cases the epiphytism approaches parasitism.
In reality, however, the families designated Eproboscidea (Hippoboscidae, Braulidae, Nycteribiidae and .Streblidae), are not entitled to be considered as constituting either a suborder, or even a main division of the Cyclorrhapha; they are simply Cyclorrhapha much modified owing to parasitism, and in view of the closely similiar mode of reproduction in the tsetseflies the special designation Pupipara should be abandoned.
Many spiderlings may succumb to nest parasitism, predation, and even cannibalism before the survivors emerge in the spring.Advertisement
In one case described by Kuckuck the chromaphores of the infesting algae are absent, a circumstance which points to a complete parasitism.
From this we may pass through various grades of " commensalism," like that of the hermit-crab with its protective anemones, to the cases of actual parasitism.
Work with Graeme Ruxton from the University of Glasgow has focused on modeling intraspecific brood parasitism in various ways.
Its appropriation of a vast share of the national income has the character of social parasitism.
The graph shows observed parasitoid success after sympatric parasitism plotted against parasitoid success as predicted by the model.Advertisement
Lambs are often treated frequently to ensure high growth rates without the negative effects of gastrointestinal parasitism.
Eosinophilia (Eos 0.8 x 109/l) is very rarely found in association with intestinal parasitism in horses.
In this project we hope to develop these ideas to the modeling of interspecific brood parasitism.
The group has until recent years been regarded as comprising three classes distinguished by well-marked physiological featuresthe Algae (including the Seaweeds) which contain chlorophyll, the Fungi which have no chlorophyll and therefore lead a saprophytic or parasitic mode of life, and the Lichens which are composite organisms consisting of an alga and a fungus living together in a mutual parasitism (symbiosis); Bacteria were regarded as a section of Fungi.
Such a relationship is known as symbiosis, and the large majority of the cases of so-called parasitism among green plants can be referred to it.Advertisement
The union taking place underground, while the bulk of both partners in the symbiosis rises into the air, renders the association a little difficult to see, but there is no doubt that the plants in question do afford each other assistance, forming, as it were, a kind of partnership. The most pronounced case of parasitism, that of Cuscuta, the dodder, which infests particularly clover fields, appears to differ only in degree from those mentioned, for the plant, bare of leaves as it is yet contair.s a little chlorophyll.
In its systematized form, as a branch of botanical study, it is of recent date, and, as now understood, the subject first received special attention about 1850, when the nature of parasitism began to be intelligible; but many disjointed references to diseased conditions of plants had appeared long before this.
Instances of what we may term tolerated parasitism, where the host plant seems to accommodate itself very well to the presence of the Fungus, paying the tax it extorts and nevertheless not succumbing but managing to provide itself with sufficient material to go on with, are not rare; and these seem to lead to those cases where the mutual accommodation between host and guest has been carried so far that each derives some benefit from the associationsymbiosis (see FUNGI).
Natural Protection Against Parasitism The living organism is a rich storehouse of the very materials from which parasites, both animal and vegetable, can best derive their nourishment.
The larch remains free from parasitism so long as its covering is intact, but as soon as this is punctured by insects, or its continuity interfered with by cracks or fissures, the Peziza penetrates, and before long brings about the destruction of the branch.Advertisement
The influence of parasitism has so profoundly influenced its structure that its affinities are obscured by the development of specialized and adaptive features.
The larch suffers from several diseases caused by fungi; the most important is the larch-canker caused by the parasitism of Peziza Willkommii.
The relation of the fungus to the alga, though it may be described in general terms as one of symbiosis, partakes also somewhat of the nature of parasitism.
The fungus seems, on the other hand, to stimulate the algal cells to special development, for those in the lichen are larger than those in the free state, but this is not necessarily adverse to the idea of parasitism, for it is well known that an increase in the size of the cells of the host is often the result of the attacks of parasitic fungi.
It must be borne in mind that the exact nutritive relations of the two constituents of the lichen have not been completely elucidated, and that it is very difficult to draw the line between symbiosis and parasitism.
In epiphytic forms the rhizoids of the epiphyte often penetrate into the tissue of the host, and certain epiphytes are not known to occur excepting in connexion with a certain host; but to what extent, if any, there is a partial parasitism in these cases has not been ascertained.
In the whole group of the Cryptonemiales the parasitism becomes more marked still.
A curious effect of parasitism, well illustrated in crabs, though not confined to them, has been expounded by Professor Giard, namely, that it tends to obliterate the secondary sexual characters.
As a matter of fact, however, the range of structural variation within the group is so wide, and the modifications due to parasitism and other causes are so profound, that it is almost impossible to frame a definition which shall be applicable to all the members of the class.
For the complicated parasitism of isopods and Sacculinidae on the same hosts Giard and Bonnier (Bopyriens, 1887, p. 197) should be consulted.
An epiphytic fungus is not necessarily a parasite, however, as many saprophytes (moulds, &c.) germinate and develop a loose mycelium on living leaves, but only enter and destroy the tissues after the leaf has fallen; in some cases, however, these saprophytic epiphytes can do harm by intercepting light and air from the leaf (Fumago, &c.), and such cases make it difficult to draw the line between saprophytism and parasitism.