Home›Lesson Plans›Science›Life Science · Grade 7

Symbiosis: How Living Things Interact

Students explore the relationships that connect organisms in an ecosystem — mutualism, commensalism, parasitism, predation, and competition — and learn to classify who benefits and who is harmed.

Grade 7Ecology55 minutes1 class period5E ModelExplicit teaching4 StandardsCommon Core
Start the Lesson
Assign or share this lesson

Copy link works with Canvas, Schoology, Moodle and any other LMS — paste it in as a resource or assignment.

Lesson at a Glance

Everything you need before the bell rings

Learning Objectives

Students will be able to…

  • ✓Define symbiosis.
  • ✓Explain mutualism, commensalism, parasitism.
  • ✓Explain predation and competition.
  • ✓Classify a relationship by who benefits.
Essential Question

A bee and a flower help each other; a tick harms a dog; a lion hunts a zebra. How do scientists classify the many ways living things interact?

0
Lesson Phases
0
Vocabulary Terms
0
Standards Aligned
0
Interactive Task
Relationship Explorer · Interactive

The Relationship Explorer

Project this and tap each type of interaction. Have students note who benefits, who is harmed, and an example of each.

🔗 Explore ecosystem interactions — tap eachTry it

The Lesson · 5E Model

55 minutes, five moves

Tap any phase to open the teacher moves and student actions.

1

Engage — Who Wins?

5 min

A bee + a flower, a tick + a dog — who benefits in each?

👩‍🏫 Teacher Moves

  • Show two interactions.
  • Ask who benefits/is harmed.
  • Set the goal: symbiosis.

🎒 Student Actions

  • Compare the pairs.
  • Ask who wins.
  • Predict the types.
2

Explore — Explore the Types

12 min

Students investigate.

👩‍🏫 Teacher Moves

  • Send students to the Relationship Explorer.
  • Tap each type.
  • Record who benefits/is harmed.

🎒 Student Actions

  • Tap each type.
  • Record it.
  • Note benefit/harm.
3

Explain — Classify the Relationship

13 min

Teacher explains.

👩‍🏫 Teacher Moves

  • Explain the +/+, +/0, +/− patterns.
  • Add predation and competition.
  • Show why interactions matter.

🎒 Student Actions

  • Explain the patterns.
  • Add predation/competition.
  • Explain importance.
4

Elaborate — Elaborate — Real Examples

12 min

Apply.

👩‍🏫 Teacher Moves

  • Classify real-world examples.
  • Explain the +/− for each.
  • Build a food-web interaction map.

🎒 Student Actions

  • Classify examples.
  • Explain each.
  • Map interactions.
5

Evaluate — Evaluate — Exit Ticket

5 min

Three quick checks.

👩‍🏫 Teacher Moves

  • Hand out the exit ticket.
  • Look for benefit/harm reasoning.
  • Collect as formative data.

🎒 Student Actions

  • Classify a relationship.
  • Explain who benefits.
  • Give an example.
Standards Alignment

Built to the standards you report on

Aligned to Next Generation Science Standards and Common Core literacy. State-standard crosswalks available on request.

NGSS
MS-LS2-2

Construct an explanation that predicts patterns of interactions among organisms across ecosystems.

NGSS
MS-LS2-1

Analyze data to provide evidence for the effects of resource availability on organisms.

NGSS
MS-LS2-4

Construct an argument that changes to an ecosystem affect populations.

CCSS
RST.6-8.7

Integrate visual information with text in a scientific model.

Differentiation

One lesson, every learner

Multilingual Learners

ELL / EMERGING READERS
  • Interaction picture cards (+/− labels).
  • Sentence frame: “In ___, ___ benefits and ___ is ___.”
  • Match examples to types.

Support & Access

IEP / 504
  • Start with mutualism vs. parasitism.
  • Use clear +/− examples.
  • Classify one at a time.

Stretch & Extend

GIFTED / EARLY FINISHERS
  • Classify tricky real examples.
  • Explain how one change ripples through a web.
  • Research a symbiotic pair.
Materials

What to gather

  • 📽️Projector / board
  • 📓Science notebooks
  • 💻The Relationship Explorer
  • 🖼️Interaction cards
  • ✏️Pencils
  • 🎫Exit-ticket slips
Vocabulary

Key terms — hover for a quick definition

symbiosisa close relationship between speciesmutualismboth species benefitcommensalismone benefits, one unaffectedparasitismone benefits, one is harmedpredationone hunts and eats anothercompetitiona struggle for the same resourcehostthe organism a parasite lives onecosystemliving things and their environment
Evaluate

Exit Ticket

Preview the three formative checks. Tap “Sample answer” to see what mastery looks like — hide them before you print for students.

QUESTION 1
In mutualism, who benefits?
Both species benefit (a win-win, like bees and flowers).
QUESTION 2
What is the difference between commensalism and parasitism?
In commensalism one benefits and the other is unaffected; in parasitism one benefits and the other is harmed.
QUESTION 3
A lion hunting a zebra is an example of what interaction?
Predation.

Going deeper? Classify the tricky ones.

Have students research real symbiotic pairs (clownfish and anemone, remora and shark) and classify each relationship. A printable classification sheet is in the Science library.

Study · Flashcards

Study the key terms

Tap a card to flip it, then rate whether you knew it. Built from this lesson’s vocabulary.

🃏 Symbiosis & Ecosystem InteractionsFlip
Card 1
Term
Tap to flip →
Meaning
0

Nice work!

Practice · Quiz

Check your understanding

A quick self-check with instant feedback, drawn from this lesson’s key terms.

📝 Symbiosis & Ecosystem InteractionsQuiz
Score: 0
1 / 6
Question 1
0%

Nice work!

Practice · Worksheet

Printable worksheet

A print-and-go review sheet with a built-in answer key. Tap “Show answer key” to reveal answers, or print the clean version for students.

🖨️ Symbiosis & Ecosystem InteractionsPrint
Name: ________________________
Date: ____________

Part A · Write the word that matches each meaning

Word bank: commensalism, competition, ecosystem, host, mutualism, parasitism, predation, symbiosis
  1. the organism a parasite lives on
  2. a close relationship between species
  3. living things and their environment
  4. a struggle for the same resource
  5. one benefits, one unaffected
  6. one hunts and eats another
  7. one benefits, one is harmed
  8. both species benefit

Part B · Show what you learned

  1. In mutualism, who benefits?
  2. What is the difference between commensalism and parasitism?
  3. A lion hunting a zebra is an example of what interaction?
Answer key — Part A: 1) host · 2) symbiosis · 3) ecosystem · 4) competition · 5) commensalism · 6) predation · 7) parasitism · 8) mutualism
Part B: 1) Both species benefit (a win-win, like bees and flowers). 2) In commensalism one benefits and the other is unaffected; in parasitism one benefits and the other is harmed. 3) Predation.