Symbiotic Symbiotic RelationshiRelationshi

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Objectives of the Symbiotic Objectives of the Symbiotic Relationships LessonRelationships Lesson

Students will investigate how organisms or populations Students will investigate how organisms or populations interact with one another through symbiotic relationships interact with one another through symbiotic relationships and how some species have become so adapted to each and how some species have become so adapted to each other that neither could survive without the other. (Ohio other that neither could survive without the other. (Ohio Academic Standards LS 7.1)Academic Standards LS 7.1)

Students will be able to define and identify the following Students will be able to define and identify the following relationships:relationships: ParasitismParasitism MutualistismMutualistism CommensalismCommensalism NeutralismNeutralism CompetitionCompetition

Symbiotic RelationshipsSymbiotic Relationships

Definition: A relationship between two Definition: A relationship between two kinds of organisms that lasts over a period kinds of organisms that lasts over a period of time is called symbiosis.of time is called symbiosis.

The word symbiosis can be broken down The word symbiosis can be broken down into two parts to determine its meaning.into two parts to determine its meaning. symsym means together (like in the words means together (like in the words

sympathy and symphony)sympathy and symphony) biobio mean life (like in the words biology and mean life (like in the words biology and

biome)biome)

ParasitismParasitism

ParasitismParasitism

Parasitism is the Parasitism is the situation where one situation where one organism benefits while organism benefits while the other is harmed.the other is harmed.

A + / - relationship.A + / - relationship. Think of a friendship Think of a friendship

where you might feel where you might feel used by your friend.used by your friend.

Parasitic Isopod on fish

TapewormsTapeworms

The definitive host of the cucumber tapeworm is a The definitive host of the cucumber tapeworm is a dog or a cat (occasionally a human). Fleas and lice dog or a cat (occasionally a human). Fleas and lice are the intermediate host. the dog or cat becomes are the intermediate host. the dog or cat becomes contaminated when the eggs are passed in the contaminated when the eggs are passed in the feces, and the flea or louse ingests the eggs.  The feces, and the flea or louse ingests the eggs.  The dog or cat (or human) is infected when they ingest a dog or cat (or human) is infected when they ingest a flea or louse.  Hence the importance of controlling flea or louse.  Hence the importance of controlling fleas on your pet!fleas on your pet!

BedbugsBedbugs Bedbugs are small, Bedbugs are small,

nocturnal parasites that nocturnal parasites that come out of hiding at come out of hiding at night to feed on night to feed on unsuspecting humans.  unsuspecting humans.  They feed exclusively on They feed exclusively on blood!  Their bites often blood!  Their bites often result in an allergic result in an allergic reaction.reaction.

Parasitism: one benefits, one is harmed

Acacia plant with ant galls

Ants lay eggs on

acacia treeAcacia

covers the infected area with

brown flesh (gall)

Parasitism: one benefits, one is harmed

Taenia worm in human eye

Worm infects human blood

streamHuman may

go blind

CommensalCommensalism ism

CommensalismCommensalism

Commensalism is Commensalism is where one species where one species benefits while the benefits while the second species second species remains unaffected.remains unaffected.A + / 0 relationshipA + / 0 relationship

Think of a friendship Think of a friendship where one of the where one of the friends benefits while friends benefits while the other doesn’t the other doesn’t change.change.

Barnacles adhering to the skin of a whale

Commensalism: one benefits, one is unaffected

Cattle with cattle egrets Cattle stir

up insects as they eat

grassEgrets hang

around and eat insects

MutualisMutualismm

MutualismMutualism Mutualism is where Mutualism is where

both organisms both organisms benefit from the benefit from the relationship.relationship.

A + / + relationship.A + / + relationship. Think of a normal Think of a normal

friendship where friendship where both friends gain both friends gain something from the something from the friendship.friendship.

The clownfish and sea anemone are an example of mutualism. Although these anemones stun and devour other species of fish, clownfish are not harmed. Clownfishes were thought to be commensal on the giant sea anemones, but there now is evidence that the aggressively territorial clownfishes chase away butterfly fishes, who eat anemone tentacles.

MutualismMutualism Both organisms benefit from the relationshipBoth organisms benefit from the relationship

The otters help the kelp by eating the sea urchins which endanger it. The kelp provides and anchor for the otters while they sleep.

Otters and Kelp

Mutualism: Mutualism: both benefitboth benefit

Moray Eel with Cleaner

FishMoray Eel gets a clean mouth Cleaner Fish gets a meal

Mutualism: both Mutualism: both benefitbenefit

Antelope with Oxbird

Antelope gets rid

of parasites Oxbird gets a meal

PredatiPredationon

What type of relationship is this? Can you guess? The picture shows a shark going after the small fishes to eat them. The small fishes are helpless! In this type of relationship, the shark is the predator, much bigger and powerful, while the small fishes are the prey. They are directly attacked by the predator. This relationship is called predation. Do you know of other examples of this type of relationships?

NeutralisNeutralismm

Neutralism is the situation Neutralism is the situation where both species remain where both species remain unaffected.unaffected.

A 0 / 0 relationship.A 0 / 0 relationship. Think of someone you sit Think of someone you sit

beside but never show any beside but never show any emotional either positive or emotional either positive or negative.negative.

NeutralismNeutralism the most common type of interspecific interaction. Neither population affects the other. Any interactions that do occur are indirect or incidental.

Example: the tarantulas living in a desert and the cacti living in a desert

CompetitiCompetitionon

Competition is where neither Competition is where neither species benefits.species benefits.

A - / - relationship.A - / - relationship. Think of someone whom you are Think of someone whom you are

constantly at battle with.constantly at battle with.

COMPETITION: COMPETITION: Scramble (Indirect) vs. Contest (Direct)Scramble (Indirect) vs. Contest (Direct)

Scramble: mutual use of limited resource

-Most plant competition is of this form

ContestContest: : interact directly (direct aggression or display)

Competition can be defined as an interaction between organisms or species, in which the fitness of one is lowered by the presence of another.

 Limited supply of at least one resource (such as food, water, and territory) used by both is required. Competition is one of many interacting biotic and abiotic factors that affect community structure

intraspecific competition - Competition among members of the same species

interspecific competition. competition between individuals of different species is known as 

AmensaliAmensalismsm

Amensalism between two species involves one impeding or restricting the success of the other while the other species has no effect on it. 

Do you know that there are organisms that may live together only for sometimebecause one species secrete a toxic or lethal substance that could kill the other species?Are you familiar with some of them? A certain species of Artemisia (damong maria) secretea substance that can kill the grasses that may grow around them. This is an example ofamensalism.

It is a type of symbiosis. Usually this occurs when one organism exudes a chemical compound as part of its normal metabolism that is detrimental to another organism.

The bread mold Penicillium is a common example of this; penicillium secrete penicillin, a chemical that kills bacteria.

A second example is the black walnut tree (Juglans nigra), which secrete juglone, a chemical that harms or kills some species of neighbouring plants, from its roots. This interaction may still increase the fitness of the non-harmed organism though, by removing competition and allowing it access to greater scarce resources. In this sense the impeding organism can be said to be negatively affected by the other's very existence, making it a +/- interaction.

A third simple example is when sheep or cattle make trails in grass that they trample on, and without realizing, they are killing the grass.

SaprophytSaprophytismism

Since one of the characteristics of fungi is that they are unable to produce their own food by photosynthesis, due to the lack of choloroplasts, they obtain their food from other organisms. They also do not have mouths to take in food as animals do, therefore they absorb food through their plasma membranes and cell walls. One of the types of such heterotrophic food intake methods is saprophytism

Effects and examplesEffects and examples

They break down wastes from dead organic matter and thereby enabling the constituent materials to be available for reuse by other organisms within the ecosystem.

dry rot, which occurs in wooden houses, and other wooden structures, causing the wood to deteriorate and the structure to fall apart

CannibalisCannibalismm

CannibalismCannibalism

Eating species of the same kind.Eating species of the same kind.

Example: Human (Holocaust)Example: Human (Holocaust)

SpiderSpider

dog eating puppies

CooperatiCooperationon

CooperationCooperation

Helping same kind of organisms or Helping same kind of organisms or organisms of different kind to get food.organisms of different kind to get food.

Example: Ants in a colonyExample: Ants in a colony honeybee colony where the

member carry out and follow specific task rigidly and work together for benefit of the group

For PracticeFor PracticeA lichen is a combination of two organisms, an A lichen is a combination of two organisms, an alga and a fungus. The fungus gets its food alga and a fungus. The fungus gets its food from the alga while the alga gets water from from the alga while the alga gets water from the fungus. This is an example of which the fungus. This is an example of which relationship?relationship?

a)a) CompetitionCompetition

b)b) MutualismMutualism

c)c) ParasitismParasitism

d)d) CommensalismCommensalism

Let’s look at this againLet’s look at this again

If this were an example of competition, If this were an example of competition, both of the organisms would be effected both of the organisms would be effected negatively. However, in this example negatively. However, in this example neither organism is effected negatively.neither organism is effected negatively.

Return to the question.Return to the question.

Good Job!Good Job!

You’re right! This is an example of a You’re right! This is an example of a mutualistic relationship. The alga gains mutualistic relationship. The alga gains water from the fungus and the fungus water from the fungus and the fungus gains food from the alga. Both need each gains food from the alga. Both need each other to live and gain something from the other to live and gain something from the other organism.other organism.

Go to the assignmentGo to the assignment

It’s interesting that you It’s interesting that you think thisthink this

In a parasitic relationship, one organism In a parasitic relationship, one organism gains a positive while the other organism gains a positive while the other organism receives a negative. In this example, receives a negative. In this example, neither organism receives a negative.neither organism receives a negative.

Return to the question.Return to the question.

Can we talk about the Can we talk about the exampleexample

In a commensalistic relationship, one In a commensalistic relationship, one organism gains something positive. The organism gains something positive. The other organism remains unaffected by other organism remains unaffected by the relationship. In this example, both the relationship. In this example, both organisms are effected by the organisms are effected by the relationship.relationship.

Return to the question.Return to the question.

X

Y

Type of interaction

0 0 Neutralism

- 0 Amensalism

+ 0 Commensalism

- - Competition

+ + Mutualism

+ - Predation orParasitism

TerminologyTerminology HerbivoryHerbivory: an animal consuming plant : an animal consuming plant

materialmaterial 4 kinds of herbivores:4 kinds of herbivores: GrazersGrazers (aka folivores) consume leafy (aka folivores) consume leafy

materialmaterial BrowsersBrowsers consume woody material and consume woody material and

barkbark GranivoresGranivores consume seeds consume seeds FrugivoresFrugivores consume fruit consume fruit