Species Interactions: Competition, Predation, and Symbiosis

Biology Grades High School 8:11 Video
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Lesson Description

Explore the diverse relationships between species in a community, including competition, predation, and the various forms of symbiosis (parasitism, mutualism, and commensalism).

Video Resource

Interactions between populations | Ecology and natural systems | High school biology | Khan Academy

Khan Academy

Duration: 8:11
Watch on YouTube

Key Concepts

  • Interspecific interactions
  • Competition
  • Predation (including herbivory)
  • Symbiosis (parasitism, mutualism, commensalism)

Learning Objectives

  • Define and differentiate between competition, predation, and symbiosis.
  • Provide examples of parasitism, mutualism, and commensalism.
  • Explain how these interactions affect population dynamics within a community.

Educator Instructions

  • Introduction (5 mins)
    Begin by introducing the concept of a community and the importance of interactions between different species. Briefly explain the terms 'population' and 'habitat' as a refresher. Engage students by asking them to brainstorm examples of interactions they have observed in nature or learned about.
  • Video Viewing (10 mins)
    Play the Khan Academy video 'Interactions between populations | Ecology and natural systems | High school biology'. Instruct students to take notes on the different types of interspecific interactions discussed.
  • Discussion: Competition and Predation (10 mins)
    Lead a class discussion focusing on competition and predation. Ask students to provide real-world examples not mentioned in the video. Discuss the +/- notation used to represent the impact of these interactions. Ask how competition for resources affects population size.
  • Discussion: Symbiosis (15 mins)
    Transition to a discussion on symbiosis. Clearly define parasitism, mutualism, and commensalism. Challenge students to think critically about commensalism, especially the idea that it may not always be a truly neutral interaction. Have students provide original examples for each type of symbiosis.
  • Activity: Interaction Classification (10 mins)
    Divide students into small groups and provide them with a list of scenarios describing different species interactions. Have each group classify the interaction as competition, predation, parasitism, mutualism, or commensalism, and justify their reasoning.
  • Wrap-up and Review (5 mins)
    Summarize the key concepts covered in the lesson. Assign the multiple choice and fill-in-the-blank quizzes as homework or an in-class assessment.

Interactive Exercises

  • Create an infographic
    Students create an infographic that visually represents the different types of species interactions, including definitions and examples.

Discussion Questions

  • How might climate change affect the interactions between species in a specific ecosystem?
  • Can an interaction between two species shift from one type (e.g., commensalism) to another (e.g., parasitism) over time? Explain with examples.
  • How can the removal of a keystone species affect interspecific interactions within an ecosystem?

Skills Developed

  • Critical thinking
  • Classification and analysis
  • Scientific communication

Multiple Choice Questions

Question 1:

Which type of interspecific interaction involves two species competing for the same resources?

Correct Answer: Competition

Question 2:

In predation, what type of effect does the predator have on the prey population?

Correct Answer: Negative

Question 3:

Which of the following is an example of herbivory?

Correct Answer: A goat eating grass

Question 4:

Which type of symbiosis benefits one species while harming the other?

Correct Answer: Parasitism

Question 5:

A clownfish living within a sea anemone, where both species benefit, is an example of:

Correct Answer: Mutualism

Question 6:

Which type of symbiotic relationship involves one organism benefiting and the other being unaffected?

Correct Answer: Commensalism

Question 7:

Bacteria living on human skin and consuming dead skin cells without causing harm is an example of:

Correct Answer: Commensalism

Question 8:

The interaction where different populations are competing for the same resources is called:

Correct Answer: Competition

Question 9:

The long-term, intimate interactions between two species are generally known as:

Correct Answer: Symbiosis

Question 10:

If two species are both negatively affected by their interaction, this is an example of:

Correct Answer: Competition

Fill in the Blank Questions

Question 1:

The technical term for interactions between different species is ______________ interactions.

Correct Answer: interspecific

Question 2:

When different species are competing for the same resources, this is called ______________.

Correct Answer: competition

Question 3:

The act of one population eating another is known as ______________.

Correct Answer: predation

Question 4:

When an animal eats a plant, this specific type of predation is called ______________.

Correct Answer: herbivory

Question 5:

Long-term, intimate interactions between species are collectively known as ______________.

Correct Answer: symbiosis

Question 6:

A type of symbiosis where one species benefits and the other is harmed is called ______________.

Correct Answer: parasitism

Question 7:

When both species benefit from their interaction, it is called ______________.

Correct Answer: mutualism

Question 8:

An interaction where one species benefits, and the other is unaffected is called ______________.

Correct Answer: commensalism

Question 9:

A __________ is an organism that benefits by living in or on a host organism, causing it harm.

Correct Answer: parasite

Question 10:

The community includes all different ___________ that are in the same habitat.

Correct Answer: populations

Educational Standards

B.LS2.2:[Standard] Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales. B.LS2.6:[Standard] 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. B.LS4.2:[Standard] Construct an explanation based on evidence that biological diversity is influenced by (1) the potential for a species to increase in number, (2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for limited resources, and (4) the proliferation of those organisms that are better able to survive and reproduce in the environment.

Teaching Materials

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