Ecological Relationships - Symbiosis

​Ecological Relationships

By L. Dalphond

​​Ecology: the study of relationships between living organisms, including humans, and their physical environment

When we speak of ecological relationships, we are referring to how organisms interact with each other.

These lessons will explore 5 different types of ecological relationships.

3 Symbiotic relationships:
- Mutualism
- Commensalism
- Parasitism

2 Other crucial relationships:
- Competition
- Predation

Let's start with the term symbiosis.

Symbiosis: a close, long-term interaction between two organisms of different species

SYM​
together

BIO
life, living

Multiple Choice

Symbiosis refers to:

• a temporary relationship between two similar species
• a competitive interaction for resources between species
• a close and long-term interaction between two different biological species
• a random occurrence of species living near each other

Match

The following root words form the word symbiosis. Match the root words to their meanings.

• SYM

• BIO

• SIS

together

life/living

action, process, state, or condition

• together

• life/living

• action, process, state, or condition

Mutualism: a relationship between organisms of different species that benefits both individuals

Mutual: the same on both sides

Multiple Choice

What do people mean when they say, "The feeling is mutual."

• It indicates one person is more interested than the other.
• It suggests that feelings are not reciprocated at all.
• It means that both people feel the same way about each other.
• It means that one person is indifferent to the other.

Mutualism: a relationship between organisms of different species that benefits both individuals

Example: Clownfish and sea anemones share a famous mutualistic symbiotic relationship. The anemone's stinging tentacles protect the clownfish from predators. In return, the fish defend the anemone, clean it, remove parasites, and provide food through waste and scraps, forming a crucial partnership for survival.

Multiple Choice

In the example of the clownfish and the sea anemone, why is the symbiotic relationship mutualistic?

• The clownfish provides shelter but receives nothing in return.
• The clownfish is harmed while the anemone benefits.
• Both species compete for the same resources.
• Both the clownfish and the sea anemone benefit from each other.

Multiple Choice

Which set of signs would represent a mutualistic symbiotic relationship?

• + / +

• - / -

• + / -

• - / +

• + / 0

Commensalism: a relationship between organisms of different species in which one individual benefits and the other is unaffected

Multiple Choice

How do mutualism and commensalism differ?

• Mutualism involves competition, whereas commensalism involves cooperation.
• Mutualism involves mutual benefits, whereas commensalism involves one benefiting without affecting the other.
• Mutualism is a type of parasitism, while commensalism is a form of predation.
• Mutualism benefits one species, while commensalism benefits both species.

Multiple Choice

Which symbols would represent a commensalistic symbiotic relationship?

• 😄😄

• 😄😐

• ☹️☹️

• 😄☹️

Multiple Choice

Which set of signs would represent a commensalistic symbiotic relationship?

• + / +

• - / -

• + / -

• - / +

• + / 0

Commensalism: a relationship between organisms of different species in which one individual benefits and the other is unaffected

Example: The cattle and egret relationship is an example of commensalism. The egret benefits from eating insects that are attracted to the cattle, while the cattle are largely unaffected (neither helped nor harmed).

Cattle: a type of cow animal
Egret: a type of bird

Multiple Choice

In the example of the cattle and the egret, why is the relationship defined as an example of commensalism?

• Both species benefit equally.

• The egret harms the cattle while feeding.

• The egret benefits while the cattle are unaffected.

• The cattle gain nutrients from the egret.

Multiple Choice

A student claims that the symbiotic relationship between the cattle and the egret is mutualistic. They use as evidence these details:

1. The egret benefits by feeding from the insects attracted to the cattle.

2. The cattle benefits by receiving free pest control from the egrets.

Although the student has selected evidence in which both species benefit from the relationship, why would the relationship still be an example of commensalism?

• Both species are equally harmed.

• The cattle are not significantly benefited or harmed by the egrets.

• The egret is the only beneficiary (the only organism to benefit), while the cattle experiences a detrimental condition from the presence of the egret.

• The egret harms the cattle.

Parasitism: a relationship between organisms of different species in which one individual benefits and the other is harmed

Multiple Choice

Which symbols would represent a parasitic symbiotic relationship?

• 😄😄

• 😄😐

• ☹️☹️

• 😄☹️

Multiple Choice

Which set of signs would represent a parasitic symbiotic relationship?

• + +

• - -

• + -

• + / 0

Parasitism: a relationship between organisms of different species in which one individual benefits and the other is harmed

Example: The Sacculina barnacle infects crabs. The barnacle larva (baby stage) burrows into the crab, grows a root system, and sterilizes the crab (preventing the crab from reproducing). The barnacle then manipulates the crab into nurturing the barnacle parasite as if it were the crab's own eggs.

Multiple Choice

Why is the example of the Sacculina barnacle and the crab an example if parasitism?

• The barnacle exploits (uses) the crab for its own benefit, harming the crab in the process.

• Both the crab and barnacle thrive together.

• The crab benefits from the barnacle's presence.

• The barnacle provides nutrients to the crab.

Multiple Choice

In parasitic relationships, one organism benefits while the other organism is harmed.

Which piece of evidence supports the claim that the crab is harmed in its relationship with the Sacculina barnacle?

• The barnacle sterilizes the crab

• The barnacle grows a root system

• The barnacle positions itself on the posterior of the crab

• The barnacle can live up to 2 years

Parasite: an organism that lives IN or ON a host organism, extracting nutrients from and harming the host in the process

Host: an organism in which or on which a parasite lives

Example:
- The Sacculina barnacle is the parasite. It lives in and on the crab.
- The crab is the host.

Drag and Drop

In the relationship between the Sacculina barnacle and the crab, the barnacle is the ​

Placeholder

and the crab is the ​

Placeholder

.

Drag these tiles and drop them in the correct blank above

parasite

host

harmed

benefits

relationship

Parasite: an organism that lives IN or ON a host organism, extracting nutrients from and harming the host in the process

Host: an organism in which or on which a parasite lives

Example:
- The Sacculina barnacle is the parasite. It lives in and on the crab.
- The crab is the host.

Fill in the Blank

Ticks are insects that burrow into the skin of animals in order to feed on their blood. Ticks are parasites.

Respond in English in one word.

An organism in which or on which a parasite lives or feeds on:

Drag and Drop

Mistletoe is a plant that grows on hardwood trees, especially oak trees. The mistletoe drains the water and nutrients from the oak trees, which potentially kills the hardwood trees. In this example, the mistletoe is the ​

Placeholder

and the oaks trees are the ​

Placeholder

.

Drag these tiles and drop them in the correct blank above

parasite

host

benefit

harm

mutual

organ

Endoparasite: a parasite that lives inside of its host

Ectoparasite: a parasite that lives outside of its host

ENDO-​
internal; within

ECTO-
external; outside

Match

Match the root words with their meanings.

• internal; within

• external; outside

• life; living

• together

• action, process, state, or condition

ENDO-

ECTO-

BIO-

SYM

SIS

• ENDO-

• ECTO-

• BIO-

• SYM

• SIS

Drag and Drop

Endoparasites live ​

Placeholder

of their hosts.

Ectoparasites live ​

Placeholder

of their hosts.

Drag these tiles and drop them in the correct blank above

inside

outside

with respect

in spite

in opposition

Fill in the Blank

Ticks are insects that burrow into the skin of animals in order to feed on their blood. Ticks are parasites.

Respond in English in one word.

Ticks are this type of parasite:

Multiple Select

A tapeworm is a long, flat, parasitic worm that lives in the intestines of animals and humans, absorbing nutrients from its host; humans get infected by eating raw or undercooked meat (beef, pork, fish) or water containing tapeworm eggs or larvae, often experiencing mild or no symptoms, though it can lead to digestive issues, fatigue, or, in rare serious cases, organ cysts. 

Which of these is true about the tapeworm?

• It forms a parasitic relationship with the human or other animal.

• It's an endoparasite.

• It forms a mutualistic relationship with the human or other animal.

• It's an endoparasite.

• It forms a commensalistic relationship with the human or other animal.

Categorize

Options (17)

Both organisms benefit

Pollinators and flowering plants

Clownfish and sea anemones

Bees and fruit-bearing plants help each other.

Cattle and egret example

Tapeworms and their hosts

Fleas and dogs

Mites and plants

Lice and humans

Heartworms and dogs

Cuckoos and other birds that push eggs out of nests to lay their own eggs in the nests

One organism benefits, the other is unaffected

One organism benefits, the other is harmed

+ / 0

positive on one side, neutral on the other

+ / +

+ / -

Organize these options into the right categories.

Mutualistic Relationship

Commensalistic Relationship

Parasitic Relationship

Drag and Drop

We have studied three types of ​

Placeholder

relationships, which are close, long-term interactions between different species.

1. In ​

Placeholder

, both species benefit.

2. In ​

Placeholder

, one species benefits while the other is ​

Placeholder

.

3. In ​

Placeholder

, one species benefits while the other is harmed.

Drag these tiles and drop them in the correct blank above

symbiotic

mutualism

commensalism

parasitism

unaffected

harmed

negatively affected

hurt

competition

predator

Directions: For the following examples, determine the type of symbiotic relationship.

Example:
- The Sacculina barnacle and the crab have a parasitic relationship, because one species benefits while the other is harmed.

Dropdown

Aphids are insects that feed on plant sap, causing plant growth to slow, leaves to wilt, and in some cases, the death of the plant.

Aphids and plants show a ​

Select answer

relationship, because ​

Select answer

in the relationship.

Dropdown

Aphids are insects that feed on plant sap, causing plant growth to slow, leaves to wilt, and in some cases, the death of the plant. Ladybugs, which also live on plants, feed on aphids.



Ladybugs and plants show a​

Select answer

relationship, because ​

Select answer

in the relationship.

Multiple Choice

Pseudoscorpions often hitch rides on the backs of large beetles. During this interaction, the beetles are unharmed. What is the ecological relationship?

• Mutualism
• Commensalism
• Parasitism
• Cooperation

Multiple Choice

A feeder fish usually follows behind sharks to pick up food scraps that sharks leave behind. The feeder fish get food and the shark is unaffected. This is an example of:

• Mutualism
• Commensalism
• Parasitism
• Decomposition

Multiple Choice

Cordyceps are a type of a fungi that hijack insects' muscular and nervous systems, eventually leading to the death of the insect. What type of relationship is this?

• Commensalism

• Predator/Prey

• Parasitism

• Competition

• Mutualism

Multiple Choice

Athlete’s foot is a fungus growing between and around human toes. The fungus gets nutrients from the human skin. Athlete’s foot causes dry, scaly skin, itching, inflammation and even blisters. What type of relationship is present between the fungus and the human?

• Mutualism
• Commensalism
• Parasitism
• Predation
• Mutualism

Multiple Choice

Red-billed oxpeckers are birds that feed on blood-sucking parasites (ticks and lice) found on an impala. The impala gets rid of parasites and the red-billed oxpeckers get nutritous dinner. What type of relationship is present between the impala and the ticks and lice?

• commensalism
• mutualism
• parasitism

• competition

Multiple Choice

Red-billed oxpeckers are birds that feed on blood-sucking parasites (ticks and lice) found on an impala. The impala gets rid of parasites and the red-billed oxpeckers get nutritous dinner. What type of relationship is present between the red-billed oxpeckers and the impala?

• commensalism
• mutualism
• neutralism
• competition
• parasitism

Multiple Choice

Mistletoe extracts water and nutrients from the oak tree to the tree's detriment (harm).  What type of relationship is present between the two species of plants?

• Mutualsim 
• Parasitism 
• Commensalism 
• Predation

• Competition

Multiple Choice

Yucca flowers are pollinated by yucca moths.  The moths lay their eggs in the flowers and the eggs hatch. The larvae eat some of the seeds, and  spread them around.  What type of relationship is present between these two species?

• mutualism, as both species benefit

• commensalism, as one species benefits and the other is unaffected

• parasitism, as one species benefits and the other is harmed

• competition, as they both fight for limited resources in the same area

• predation, as one species hunts and consumes the other

Multiple Choice

Golden Jackals will trail a tiger to feed on the remains of the tiger's kill. What type of symbiotic relationship between the jackal and the tiger would this relationship exemplify?

• commensalism: one organism benefits, the other is unaffected

• mutualism: both organisms benefit

• parasitism: one organism benefits, the other is harmed

• competition

• predation

Multiple Choice

The pearl fish using the sea cucumber to hide is an example of

• Mutualism

• Commensalism

• Parasitism

• Metabolism

Multiple Choice

A cactus and the bat that pollinates its flowers is an example of....

• Mutualism

• Commensalism

• Parasitism

• Metabolism

Multiple Choice

Barnacles are sea creatures that create a home by attaching themselves to whales. The whales are largely unaffected by the barnacles, as the barnacles do not feed off of the whales. Which term best describes this symbiotic relationship?

• Commensalism

• Parasitism

• Predation

• Mutualism

Multiple Choice

Barnacles are sea creatures that create a home by attaching themselves to whales. The whales are largely unaffected by the barnacles, as the barnacles do not feed off of the whales. Which piece of evidence explains why the whale-barnacle relationship is not parasitic, even though the crab-barnacle relationship we explored earlier was a parasitic relationship?

• The barnacles harm the whales.
• The barnacles consume whale tissue.
• The barnacles grow larger on the whales,.

• The whales are largely unaffacted, because barnacles do not feed off the whales.

Multiple Choice

Ostriches and gazelles are two animals that live in Africa. They graze for food near each other because they help each other spot predators. The gazelle has excellent eyesight, but poor hearing, and the ostrich has excellent hearing, but poor eyesight. These two animals will alert one another when danger is near. Which term best describes this relationship?

• Predation

• Commensalism

• Mutualism

• Parasitism

Multiple Choice

Silverfish (insects) live and hunt with army ants. The two species share the prey. The silverfish neither help nor harm the ants. What type of relationship is present between the two species of insects?

• Mutualism

• Parasitism

• Commensalism

• Predation

Multiple Choice

A tick and a dog have this type of relationship.

• mutualism
• commensalism
• neutralism
• parasitism
• Competition

Match

The ocean sunfish is a large, flat fish that spends most of its time in deep water feeding mainly on jellyfish. Sunfish often have many species of copepods (small crustaceans) that bury their heads into the soft tissue of the sunfish. Sunfish will swim to the surface of the water and lie sideways allowing seabirds to eat the copepods from their skin. Match the organism to the correct description of how each organism is related to the sunfish.

• Seabirds

• Jellyfish

• Copepods

Mutualism

Predation

Parasitism

• Mutualism

• Predation

• Parasitism

• Predation involves an organism hunting, killing, and eating another (prey), usually being larger and killing it quickly, while parasitims involves a smaller parasite living on or inside a host, deriving nutrients without immediately killing it, as the host needs to remain alive for the parasite to survive and reproduce.
  
  * The key difference is the outcome: predators kill for immediate consumption (surplus killing), whereas parasites harm but typically keep their host alive for extended resource use

Open Ended

Consider the relationship that humans have with the Earth and its living systems. What type of symbiotic relationship do you think we have with Mother Earth: mutualistic, commensalistic, or parasitic?

Explain.