Exploring Ecology and Interactions in an Ecosystem

Species Interactions: Commensalism, Mutualism, Parasitism

Each student should have some prior knowledge about species interactions (predator and

prey relationship, herbivore, carnivore, etc.)

Each student should have some prior knowledge about types of interactions (Both species

agree, one benefits, they both do not benefit, etc.)

Each student should have some prior knowledge about examples of species interactions

(Types of predators, prey, etc.)

NGSS Standard: HS-LS2-6:

“Evaluate the claims, evidence, and reasoning that the complex interactions in

ecosystems maintain relatively consistent numbers and types of organisms in stable

conditions, but changing conditions may result in a new ecosystem”

Colorado Standard: 2.2 High School Life Science

“The size and persistence of populations depend on their interactions with each other and

the abiotic factors in an ecosystem.”

“How do keystone species maintain balance in ecosystems?”

Learning objectives: Students will be able to (SWBAT):

Demonstrate understanding of the various roles that animals/organisms play in the

environment along with what roles they play in the world by explaining explain 4 species

interactions in which they learned from their home group.

Define each type of species interactions in their own words supported by examples in

their notebook.

Learn the information at the station they are assigned and teach their home group

members what they memorized and produced from the lab.

Materials

Lesson Plan: http://teachers.net/lessons/posts/3036.html

Video: https://www.youtube.com/watch?v=xNm7dg3BiyU (Start 10 seconds in to video)

Instructional planning:

Print pages for each station

Have resources like a textbook about species interactions or scientific magazines.

Procedure

Student Activity Teacher Activity

Engage Watch video and write down important vocabulary terms that come up in the video in their science notebook for later discussion.

These can be words they do not know and what they know already. Create a table with words they know, do not know and definitions.

Known Don’t knowWords and definition

Words(Definition to fill in later)

Have students come up and write one word on the board. This will be used as a word bank for the lab

Define parasite, mutualism and commensalism with the class.

Video: start 10 seconds into clip

https://www.youtube.com/watch?v=xNm7dg3BiyU

Fill in the rest of the word bank on the board with the vocabulary on the worksheet.

Explore Get in home groups

Split into lab groups

Read resources and fill in the questions using word bank

Choose home groups by a deck of cards already counted out with same number of each suit. All hearts work together, all diamonds, etc.

Split students into home groups (groups they will come back to and explain what they learned to one another later)

Have everyone in each home group number one to four. These are the numbers they will use to go to the lab

group.

Explain In their lab group students should be reasoning with one another as to what they think the correct answer is.

Correct any wrong answers if the teacher tells you to try again.

Explain correct answers before students report back to their home groups and teach their classmates the definitions.

Go to each lab group and make sure they have the correct answers on their worksheet. If not, guide them towards the correct answer and tell them to try again.

Elaborate Students go back to their home groups to explain and summarize the information they learned with their peers.

Students will then fill in the rest of the information on the worksheet from stations they did not go to.

Ex: Group one defines what Commensalism and Mutualism are and then give examples to their peers. Those who did not go to that station will fill in this information.

Facilitate student discussion in the groups.

Ask them to give examples of the species interactions. Ask students to compare and contrast interactions.Ask what students learned, already knew, and want to know more about.Ask which type of interaction they want to explore more on another day.Ask what they thought of the activity.

Evaluate Students must write on a piece of paper and explain in their own words species interactions they learned during the activity.

Ask students to take out a piece of paper for a quiz.

Use this as their ticket out the door.

Quiz:

Define the following and give examples of each.

Commensalism, Mutualism, Symbiosis and Parasitism.

Assessment:

Formative: Students will have written their answers to the worksheet questions they were given in lab. Have students turn this sheet in for grading.

Summative: Quiz at the end of class to check for each student’s understanding of the concepts they did not teach themselves about.

Anticipated misconceptions

Students may come with the misconception that symbiosis and mutualism are interchangeable. Explain that symbiosis is a long term relationship between two or more species and that mutualism is a type of symbiosis. Mutualism and commensalism and parasitism are all examples of a type of symbiosis.

Students may come with the misconception that predation is similar to parasitism in that one organism benefits and the other is harmed. Explain to students that symbiosis is a long term relationship between organisms and this means that the short term relationship between predator and prey is not a symbiotic relationship. Explain what a parasite and host are to help explain parasitism and the differences compared to predation. Use examples. Also explain that predation results in death for the prey, but parasitism results in the host staying alive.

Accommodations/modifications

Since the students are working in groups they should be able to teach one another the information fairly well, but if students would rather work alone print all the station information out and have students go to each station. This will allow those who work faster or already understand some of the material to work at their own pace.

The lesson can also have regional examples included in the examples. This will help students connect to the lesson more because they may encounter the animals used in the worksheet.

Group 1

Photo Credit

Question 1

______________________ is the ecological

interaction in which one species benefits and

the other is neither armed nor helped.

Example: Birds use tree branches for

roosting sites. The trees get nothing but are

not harmed.

Give two more examples

Example:

Example:

Picture Credit

Question 2

______________________is the symbiotic

associations in which both partners benefit.

Example: Clownfish and sea anemone. The

tentacles around the mouth of the sea

anemone will be used to eat many fish, but

not the clownfish. The clownfish swim out

and capture food, then return to the tentacles

(which protect them from predators) and the

sea anemone will eat food scraps that fall

from the mouth of the fish.

Give two more examples

Example:

Example:

Group 2

Photo Credit

Question 1

______________________is the ecological

interaction in which individuals that belong

to the same population compete for a share

of resources in their habitat.

Example: Two solitary jaguars fighting over

a large rodent.

Give two more examples

Example:

Example:

Photo Credit

Question 2

_____________________is an ecological

interaction in which one organism feeds on

another.

Example: Caterpillar eats leaves from a wild

lilac.

Give two more examples

Example:

Example:

Group 3

Photo Credit

Question 1

______________________is a type of

predation in which the predator feeds on but

usually does not kill a larger organism.

Example: Ticks that suck the blood of deer.

Give two more examples

Example:

Example:

Photo Credit

Question 2

____________________is the ecological

interactions in which two or more species

live together in a close, long-term

association.

Example: An oxpecker bird living on a

hippo’s back.

Give two more examples

Example:

Example:

Group 4

Picture Credit

Question 1

______________________is when two or

more species that compete for the same

resource, a sharing of the resource in

different ways or at different times, which

allows them to coexist. Differences in

adaptations allow for this to happen.

Example: Lions hunt gazelle at night and

cheetahs hunt gazelle during the day.

Give two more examples

Example:

Example:

Photo Credit

Question 2

______________________are when the

individuals of one species cannot grow and

reproduce in the absence of intimate

dependency with individuals of another

species during the life cycle.

Example: The interaction between yucca

plants and yucca moths. Each yucca plant

can be pollinated only by one species of the

yucca moth

Give one more example

Example:

Answer Sheet

Group 1

Question 1

Commensalism is the ecological interaction in which one species benefits and the other is neither armed nor helped.

Example: Birds use tree branches for roosting sites. The trees get nothing but are not harmed.

Question 2

Mutualism is the symbiotic association in which both partners benefit

Example: Clownfish and sea anemone. The tentacles around the mouth of the sea anemone will be used to eat many fish, but not the clownfish. The clownfish swim out and capture food, then return to the tentacles (which protect them from predators) and the sea anemone will eat food scraps that fall from the mouth of the fish.

Group 2

Question 1

Interspecific Competition is the ecological interaction in which individuals that belong to the same population compete for a share of resources in their habitat.

Example: Two solitary jaguars fighting over a gazelle.

Question 2

Predation is an ecological interaction in which one organism feeds on another.

Example: Caterpillar eats leaves from a wild lilac flower.

Group 3

Question 1

Parasitism is a type of predation in which the predator feeds on but usually does not kill a larger organism.

Example: Ticks that suck the blood of deer.

Question 2

Symbiosis is the ecological interaction in which two or more species live together in a close, long-term association.

Example: Bird living on a hippo’s back.

Group 4

Question 1

Competitive Exclusion is the theory that two or more species that require identical resources cannot coexist indefinitely.

Question 2

Resource Partitioning is when two or more species that compete for the same resource, a sharing of the resource in different ways or at different times, which allows them to coexist. Differences in adaptations allow for this to happen.

Example: Lions hunt gazelle at night and cheetahs hunt gazelle during the day.

Question 3

Obligatory interactions are when the individuals of one species cannot grow and reproduce in the absence of intimate dependency with individuals of another species during the life cycle.

Example: The interaction between yucca plants and yucca moths. Each yucca plant can be pollinated only by one species of the yucca moth

Vocabulary List

1) Feeding Levels—the trophic levels.

2) Niche—functional role of a species in an ecosystem.

a) Sum total of all activities and relationships in which individuals of a species engage as they

secure and use the resources required to survive and reproduce.

b) Two Types:

i) Fundamental Niche—one that might prevail in the absence of competition and other factors

that could constrain its acquirement and use of resources.

ii) Realized Niche—shifts in large and small ways over time, as individuals of the species

respond to a mosaic of changes.

3) Species Interactions

a) Commensalism—ecological interaction in which one species benefits and the other is neither

armed nor helped.

b) Mutualism—symbiotic association in which both partners benefit.

c) Interspecific Competition—ecological interaction in which individuals that belong to the

same population compete for a share of resources in their habitat.

d) Predation—an ecological interaction in which one organism feeds on another.

e) Parasitism—type of predation in which the predator feeds on but usually does not kill a larger

organism.

f) Symbiosis—ecological interaction in which two or more species live together in a close, long-

term association.

g) Intraspecific Competition—ecological interaction in which individuals that belong to the

same population or species compete for a share of resources in their habitat.

h) Competitive Exclusion—theory that two or more species that require identical resources

cannot coexist indefinitely.

i) Resource Partitioning—of two or more species that compete for the same resource, a sharing

of the resource in different ways or at different times, which allows them to coexist.

j) Obligatory—some forms of mutualism.

i) The individuals of one species cannot grow and reproduce in the absence of intimate

dependency with individuals of another species during the life cycle.