Symbiosis

Symbiosis  - Symbiosis is a close relationship that may occur when two organisms of different species live together. 

Symbiotic relationships.   There are many different kinds of symbiotic relationships:

Mutualism: Both species benefit. The two organisms help each other. An example would be a honey bee and a dandelion. The honey bee gets to eat the pollen from the flower. The dandelion uses the bee to spread its pollen to another flower.

 

Commensalism: One species benefits. The other species is unaffected. A common example is an animal using a plant for shelter. An American Robin benefits by building its nest in a Red Maple tree. The tree is unaffected.

 

Parasitism: Ones species benefits. The other species is harmed. An example would be a deer tick and a White-tailed Deer. The tick gets food from the deer without killing it. The deer is harmed by losing blood to the tick, and possibly by getting an infected wound.

 

Neutralism: Neither species benefits or is harmed. Both organisms are unaffected. An American Goldfinch is a bird that eats mostly seeds. It may share a tree with a Great Crested Flycatcher, which eats mostly insects. Neither affects the other.

Cleaning Symbiosis: The drawing shows the Nile crocodile opening its mouth to permit the Egyptian plover to feed on any leeches attached to its gums. Cleaning symbiosis is more common in fish.

Epiphytes: Epiphytes are plants that live perched on sturdier plants. They do not take any nourishment from their host and simply benefit from being better exposed to sunlight.

Some examples:

• many orchids
• many bromeliads (e.g., "Spanish moss" and other members of the pineapple family).

The Evolution of Symbiosis

It seems plausible that what begins as a parasitic relationship might over the course of time evolve into a mutualistic one as the two organisms evolve to minimize the damage to the host.

And there is some evidence for this. In 1966, K. W. Jeon discovered a culture of amoebas that had become infected with bacteria (60,00 to 150,000 per cell). The infection slowed their rate of growth and made them much more fragile. But five years later, the amoebas still were infected but now no ill effects could be seen. Most interesting for our question, the amoebas — or at least their nuclei — had become dependent on the bacteria.

• When the nucleus was removed from an infected amoeba and replaced with one from a uninfected strain, the combination worked fine.
• But when the nucleus from an uninfected cell was replaced with one from an infected cell, the combination usually failed to survive.

Table of Types of symbiosis.  

Mutualistic Relationship	Organisms Involved	Interaction of organisms involved
Root Nodules	Legumes/Rhizobium	Rhizobium gets carbohydrates & provides fixed forms of nitrogen and ammonia to the legume
Lichen	Fungus/algae or cyanobacterium	Fungus sends acids to the rock and dissolves minerals. Alga or cyanobacterium carries on photosynthesis
Trichonympha/Pyrsonympha	Termite/Trichonympha and Pyrsonympha	The Trichonympha and Pyrsonympha digest wood for the termite.
Ants and Acacia	Ants/acacias	Ants feed from acacia nectaries and eat beltian bodies/nodules. Ants protect the acadia from herbivores and girdle branches to let more light in to the acacia.

Table describing types of commensalisms.   

Mutualistic Relationships	Organisms Involved	Interaction of the organisms involved
Epiphytes	Epiphytes - Various mosses, ferns, bromeliads, and orchids/Other plants.	Epiphytes grow on other plants obtaining nutrients from rainwater and decaying leaves –not from the host.
Remora	Remora/Fish (sharks) and turtles	Attaches to sides of other fish and turtles and eats food they drop.
Clown fish	Clown fish/ Sea anemone	The clown fish lives among the deadly tentacles of a sea anemone and eats food left by the sea anemone.
Barnacles	Barnacles/whales and manatees, ships and other things in the ocean.	Barnacles attach as harmless hitchhikers. Some species of  barnacles are found only as commensals on the jaws of whales. And there are other species of barnacles found only as commensals on those barnacles. Barnacles on top of  barnacles!

Parasitism table. 

Name of Parasite  Common name/ Scientific Name	Phylum of Parasite	Method of transmission	Symptoms of Disease	Intermediate  Host
Plasmodium/ P. falciparum/ P. vivax/  P. ovale	Orthonectidea	Mosquitos bites to humans	Symptoms of malaria include fever and flu-like illness, including shaking chills, headache, muscle aches, and tiredness. Nausea, vomiting, and diarrhea may also occur. Malaria may cause anemia and jaundice (yellow coloring of the skin and eyes) because of the loss of red blood cells. Infection with one type of malaria, P. falciparum, if not promptly treated, may cause kidney failure, seizures, mental confusion, coma, and death.	Mosquitoes
Tapeworm/ Tatenia pisiformis	Platyhelminthes	Pigs to humans	Abdominal pain or diarrhea and excess gas after becoming infested with tapeworm. Also may experience nausea and vomiting anal itching or inflammation, hunger, fatigue, loss of appetite, and weight loss occur if the condition is not treated. Rarely other organs of the body, including the brain, can be affected.	Pigs
Flukes/ Nanophyetus salmincola or N. schikhobalowi	Platyhelminthes	Snails to humans	Symptoms characterized by an increase of bowel movements or diarrhea, usually accompanied by increased numbers of circulating eosinophils, abdominal discomfort and nausea. A few may notice weight loss and fatigue, and some may be asymptomatic. The rickettsia, though fatal to 80% of untreated dogs, is not known to infect humans.	Snails
Hookworm/ Ancylostoma duodenale or Necator americanus	Nematoda	Contaminated soil or stool	Often no symptoms.  May be a local irritation of the skin where the worm penetrated or even an itchy rash. In the lungs, there may be asthma-like symptoms or pneumonia. The most common symptoms of Hookworm infection, however, are from their residence in the intestine. Here, Hookworm can lead to abdominal pain, diarrhea, weight loss, loss of appetite and excessive gases. In chronic infections, the patient may become anemic as the worms feed on the individual's blood. The loss of blood leads to a loss of iron and protein; causing difficulty in breathing, pale complexion, tiredness and weakness, fast heartbeat, generalized swelling or bloating and impotence. If the infection lasts a very long time or is very severe, there may be a slow growth, heart problems or even heart failure.	Soil or stool

Three types of symbiotic relationships on the basis of potential harm to a host organism.

        a.        mutualism:            symbiont benefits and host benefits
        b.        commensalisms:   symbiont benefits and host is unaffected
        c.        parasitism:            symbiont benefits and host is harmed

  Composition of a lichen and why this composition is usually considered a mutalistic relationship.

The fungus sends acids into the rock and dissolves minerals, while the alga or cyanobacterium carries on photosynthesis.

  Relationship between an epiphyte and a tree is considered commensalistic.

The epiphyte is benefited and the tree is unaffected.

 Types of organisms, give examples of a parasite.

a.  Protozoan:  Plasmodium: P. falciparum/ P. vivax/P. ovale
b.  Flatworm:   Tapeworms/Flukes: Nanophyetus salmincola an N. schikhobalowi    
c.  Roundworm  Trichinella: Nematoda  and Acanthocephala

Symbiosis I

Symbiosis II

Bacteria - Animal Symbiosis

Symbiosis - Wikipedia, the free encyclopedia

>Please visit our 101 Science Store<

---

Return to 101science.com