Obligatory relationship definition google

The Many Types of Symbiosis | HowStuffWorks

obligatory relationship definition google

The traditional definition of symbiosis is a mutually beneficial relationship involving close physical contact between two organisms that aren't the same species. Definition of relationship - the way in which two or more people or things are connected, or the state of being connected. Symbiotic relationship synonyms, Symbiotic relationship pronunciation, Symbiotic relationship translation, English dictionary definition of Symbiotic ( Biology) a close and usually obligatory association of two organisms of different species.

Shelter mutualism- human beings require bacteria in their digestive system while on the other hand they provide shelter to bacteria. Thus, the digestive mechanism in human beings is mutually beneficial to both hosts and the bacteria. Defense mutualism- ants provide defense to the acacia plants against browsers while at the same time the ants obtain food from these host plants. Both organisms benefit from this form of symbiotic relationship.

Transport mutualism- bees carry the pollen from one flower to the other and this process facilitates cross pollination. This encourages flowering and ultimately growth of other species that are required in the ecosystem. The major notable aspect about the mutualistic relationships outlined above is that they are obligatory. This implies that they are dependent on each other. Each organism requires the other for their survival.

Parasitism - Definition, Types and Examples | Biology Dictionary

This is meant to create a fine balance in the ecosystem where different organisms can depend on each other for their survival. Key features of Commensalism Commensalism represents a kind of relationship where two or more organisms coexist only one organism will benefit from the association.

Interestingly, the other part that does not benefit is not harmed by this kind of relationship and it is referred to as the host organism. Essentially, in a commensalistic relationship the other part benefits in form of obtaining nutrients, shelter, support as well as transport. Precisely, this form of relationship is divided into the following categories.

obligatory relationship definition google

Inquilinism- in this kind of relationship, one organism seeks shelter from the host organism but it does not harm it. For example, trees provide permanent shelter to epiphytic plants which grow on them but there is no harm caused on the host organisms. Metabiosis- in this form of commensalistic relationship, the host organism provides habitat to the other partner but there is no harm caused to the host organism. Hermit crabs for instance can use dead gastropods as their habitat and no harm is caused to the host organism.

Phoresy- in this relationship, the host organism provides transport to the other organism but there is no harm caused on the partner carrying the other.

Birds for example provide transport to millipedes but they are not harmed in the process. Microbiota- other organisms form communities with the host partner. For example, pilot fishes ride on a shark in order to obtain food but they do not harm the host organism. Essentially, commensalism is a relationship that involves two or more organisms but only one of them benefit from that kind of association. In this partnership, it can be observed that the host organism that provides shelter or transport to other organisms is not harmed.

Table showing the difference between mutualism and commensalism Mutualism Commensalism Form of symbiotic relationship between two or more organisms where they all benefit. If they're generating and sharing enzymes, proteins, gases or other chemicals then they can also said to be symbiotes. Endosymbiotes live inside another organism.


And by inside, biologists really mean inside -- in between cells or within the body tissues like the acoel flatworm. Ectosymbiotes live on the body of another organism. Note that organisms that live within another's digestive tract are considered ectosymbiotes.

Obligatory | Definition of Obligatory by Merriam-Webster

Apparently living in someone's else's intestines doesn't qualify as a close enough relationship for biologists to call them endosymbiotes. No Fungus, No Tree Plants and fungi occupy completely different categories in taxonomy. Over time, they have evolved so that they can no longer exist without the existence of the host. Obligate parasitism can be found in many different types of organisms, like plants, animals, fungi, bacteria, and viruses.

Head lice are obligate parasites; if removed from the human scalp, they will soon die.

obligatory relationship definition google

Facultative Parasitism Facultative parasites do not rely on the host in order to complete their life cycle; they can survive without the host, and only sometimes perform parasitic activities. Certain plants, fungi, animals, and microbes can be facultative parasites. A specific example is the nematode species Strongyloides stercoralis.


This is a type of roundworm that can cause the disease strongyloidiasis when it infects humans, but it can also be found free-living. Endoparasites, like nematodes and hookworms, live inside the host. Macroparasitism Versus Microparasitism Macroparasites are parasites that are large enough to be seen with the naked eye.

Microparasites are too small to be seen and must be viewed under a microscope.

obligatory relationship definition google

They are generally unicellularsuch as protozoa. Monogenic Versus Digenetic Monogenic parasites complete their life cycle in only one individual host. Digenetic parasites need more than one host to complete their life cycle. Plasmodium vivax, the protozoa that carries malaria, is digenetic.

obligatory relationship definition google

In order to complete its life cycle, it must be a parasite of both people and mosquitos. Epiparasitism An epiparasite is a parasite that parasitizes another organism that is also a parasite.

Epiparasites are also called hyperparasites or secondary parasites. One example would be a protozoan living in a flea that is living on a dog. Social Parasitism Social parasites take advantage of social insects like ants, bees, and termites. They may use mimicry to invade the hive.

  • How Symbiosis Works
  • Symbiotic Relationships: Mutualism, Commensalism & Parasitism
  • Parasitism

One ant species, Tetramorium inquilinum, is a parasite that spends its entire life on the back of other species of ants, essentially making the host species its slaves.