Wild Connections Assessment
ILEARN Biology • General Ed Check Standard IAS B.3.1 / HS-LS2-6
Form G-1 • Ecosystem Relationships
Wild Connections Assessment
Ecological Interactions: Mutualism, Commensalism, Parasitism & Competition
Name:
Date:
Period:
Student Reference Guide: The 4 Key Relationships + = Benefits | - = Harmed | 0 = Unaffected (No Effect)
Mutualism (+ / +) Both organisms help each other and benefit.
Commensalism (+ / 0) One benefits, and the other is not helped or harmed.
Parasitism (+ / -) One benefits by taking nutrients and harming the host.
Competition (- / -) Both struggle and lose energy over the same resource.
Question 1 Scenario Investigation • Acacia Trees and Ants
1 Point
In Central America, bullhorn acacia trees produce hollow thorns and sweet nectar on their leaves. A species of ant lives inside the hollow thorns and drinks the sweet nectar. In return, the ants swarm out and sting caterpillars, beetles, and deer that try to eat the tree's leaves. Scientists tested what happens when ants are removed from the trees:
| Tree Group | Ant Status | Leaf Damage from Insects | Tree Survival Rate |
|---|
| Group 1 | Ants Present | Only 4% damage | 88% survived |
| Group 2 | Ants Removed | Heavy 55% damage | Only 14% survived |
Based on the data, what type of ecological relationship exists between the acacia tree and the ants?
A Mutualism (+/+), because the ants get food and shelter while defending the tree so it can survive.
B Commensalism (+/0), because the ants get a home, but the tree is unaffected by having ants.
C Parasitism (+/-), because the ants steal sweet nectar from the tree and make the tree sick.
D Competition (-/-), because both the ants and the tree are fighting for the same sunlight.
Question 2 Scenario Observation • Clownfish and Sea Anemones
1 Point
Clownfish live safely among the stinging tentacles of sea anemones on coral reefs. The clownfish has a protective slime coat that keeps it from getting stung. The stinging tentacles protect the clownfish from larger predator fish. In return, the clownfish chases away butterflyfish that eat anemone tentacles, and clownfish waste provides valuable fertilizer nutrients that help the anemone grow.
Why do marine biologists classify the relationship between the clownfish and the sea anemone as mutualism?
A Both species benefit: the clownfish receives safe shelter, and the anemone receives protection and nutrients.
B One species benefits while the other is harmed: the clownfish slowly eats the anemone's stinging tentacles.
C One species benefits while the other is unaffected: the clownfish gets shelter, but the anemone gains nothing.
D Both species are harmed: the clownfish and the anemone fight each other for floating shrimp.
ILEARN Biology Diagnostic Check Turn to Page 2 → Page 1 of 5
Wild Connections Assessment • Section 2: Commensalism in Nature
Student Name:
Question 3 Marine Scenario • Barnacles and Humpback Whales
1 Point
Whale barnacles are small shelled animals that attach themselves to the skin of giant humpback whales. The barnacles cannot swim on their own. As the whale swims through the ocean, water rushes past the barnacles, allowing them to filter out tiny floating plankton to eat. Marine biologists examined the skin beneath the barnacles and found no cuts, no infections, and no change in the whale's swimming speed or health.
Which statement best explains why this relationship is an example of commensalism (+/0)?
A The barnacles benefit by traveling to rich feeding waters, while the whale is completely unharmed and receives no effect.
B Both animals benefit because the barnacles clean harmful algae off the whale's skin.
C The barnacles act as harmful parasites that slowly suck blood and energy from the swimming whale.
D The whale benefits by eating the barnacles when other food sources become scarce.
Question 4 Field Evidence • Cattle Egrets and Grazing Bison
1 Point
Cattle egrets are white birds that walk through grassy pastures alongside grazing American bison. As heavy bison step through tall prairie grass, their hooves disturb insects, flushing grasshoppers and crickets into the air. The egrets quickly catch and eat the jumping insects. Ecologists measured how this affects both animals:
• Egret Insect Catch Rate: 1 bug/minute alone → 4 bugs/minute near bison • Bison Health & Weight: No measurable change in grass eaten or body weight
Based on these observations, how should scientists classify the relationship between the egrets and bison?
A Commensalism (+/0), because the egret easily catches more food, while the bison experiences neither help nor harm.
B Mutualism (+/+), because both the egret and the bison gain nutritional energy from eating the grasshoppers.
C Parasitism (+/-), because the egret steals food away from the bison and makes the bison lose weight.
D Competition (-/-), because both animals fight directly against each other for territory in the pasture.
ILEARN Biology Diagnostic Check Turn to Page 3 → Page 2 of 5
Wild Connections Assessment • Section 3: Parasitism in Ecosystems
Student Name:
Question 5 Plant Scenario • Mistletoe and Oak Trees
1 Point
Mistletoe is a green plant with sticky white berries that grows high in tree branches. Instead of growing roots into the dirt, mistletoe grows root-like pegs directly through the tree bark and taps into the tree's water tubes. Biologists studied oak branches with mistletoe compared to healthy branches on the same tree during a hot, dry summer:
Branch Growth (Wood Width) Healthy branches: 3.4 mm vs. Mistletoe branches: 1.1 mm (growth dropped by 68%)
Water Stress During Drought Healthy branches: Normal water vs. Mistletoe branches: Severely dried out
How does this evidence prove that mistletoe is a parasite (+/-) on the oak tree?
A The mistletoe benefits by taking water and minerals, which harms the oak tree by stunting its growth and drying it out.
B Both plants benefit by trading sugar and water back and forth through the tree branch.
C The mistletoe uses the branch only for physical support without taking any resources or causing any harm.
D The oak tree acts as a predator that quickly kills and digests the mistletoe roots.
Question 6 Animal Scenario • Deer Ticks and White-Tailed Deer
1 Point
In Indiana woodlands, deer ticks attach to the skin of white-tailed deer. The tick bites through the deer's skin and drinks its blood for several days until it is full. When hundreds of ticks feed on one deer, the deer can lose significant amounts of blood, suffer skin infections, and become infected with harmful bacteria (such as the bacteria that cause Lyme disease).
Which statement best explains why this interaction is classified as parasitism?
A The tick benefits by getting nutrients (blood) from the deer, while the deer is harmed by blood loss and infection.
B Both organisms benefit because the tick eats dead skin cells to keep the deer's coat clean.
C The tick benefits by catching a ride through the woods, while the deer experiences zero effects.
D Both animals lose energy because they constantly fight over territory in the forest.
ILEARN Biology Diagnostic Check Turn to Page 4 → Page 3 of 5
Wild Connections Assessment • Section 4: Competition & Two-Part Synthesis
Student Name:
Question 7 Laboratory Data • Food Competition in Protozoans
1 Point
A biology class raised two microscopic single-celled organisms, Species A and Species B, in test tubes. Both species eat the exact same food: bacteria. When grown in separate tubes with plenty of food, both species grew large, healthy populations. But when placed together in the same tube with a limited daily food supply, Species A ate faster and grew quickly, while Species B steadily starved and died out completely after 16 days.
Which biological interaction caused Species B to die out when both organisms were placed together in the same tube?
A Interspecific competition (-/-), because both species fought for the same limited food, and Species A outcompeted Species B.
B Mutualism (+/+), because Species A shared food with Species B until all bacteria were gone.
C Commensalism (+/0), because Species A ate the food without causing any effect on Species B.
D Parasitism (+/-), because Species A lived as a disease inside Species B.
Question 8 ILEARN Two-Part Evidence Item
2 Points Total
Zebra mussels are small invasive clams that accidentally spread into Indiana freshwater lakes. Each zebra mussel filters up to 1 liter of lake water per day, eating up the microscopic green algae that native mussels need to eat. Zebra mussels also attach themselves in thick clumps directly onto the shells of native mussels, gluing their shells shut so the native mussels cannot open to breathe or feed.
Part A: What type of ecological interaction occurs between the invasive zebra mussels and native freshwater mussels?
A Competition for food (algae) and physical harm from growing heavily on the native mussels' shells.
B Mutualism, because both types of mussels help clean the water for each other.
C Commensalism, because zebra mussels get a place to sit while native mussels are completely unaffected.
D Predation, because zebra mussels hunt and eat adult fish swimming in the lake.
Part B: Which piece of biological evidence provides the strongest support for the answer in Part A?
A Native mussel populations dropped by over 90% as algae supplies fell and native shells were trapped shut by zebra mussels.
B Native mussel populations doubled in size because zebra mussels kept them warm in the winter.
C Zebra mussels stopped eating algae and only ate dirt from the lake bottom.
D Both species shared food equally and lived in harmony across all Indiana waterways.
ILEARN Biology Diagnostic Series • IAS B.3.1 / HS-LS2-6 Turn to Page 5 → Page 4 of 5
ILEARN Performance Task Section 5: Interaction Matrix Analysis
Student Name:
Question 9 Table Completion Item • Multi-Scenario Analysis
4 Points Total
Directions: Read each ecological scenario below. For each row, complete the table by:
- Writing the correct effect symbol in each box: + (Benefits), - (Harmed), or 0 (Unaffected / Neutral).
- Writing the correct ecological relationship name from the Word Bank below.
- Writing a brief 1-sentence explanation of how the organisms interact.
Relationship Word Bank: Mutualism | Commensalism | Parasitism | Competition
| Ecological Scenario | Org. 1
(+ / - / 0) | Org. 2
(+ / - / 0) | Relationship
(From Word Bank) | Biological Evidence & Reasoning
(Why does this effect happen?) |
| --- | --- | --- | --- | --- |
|
1. Honeybees & Apple Flowers
Honeybees gather sweet nectar and pollen to feed their colony. As bees fly between flowers, pollen rubs off onto other blooms, allowing apple trees to produce seeds and fruit.
|
Honeybee |
Apple Tree |
|
|
|
2. Spanish Moss & Cypress Trees
Spanish moss drapes over high cypress branches to reach sunlight. The moss absorbs rain and dust from the air without taking sap from the tree, leaving the tree completely unharmed.
|
Spanish Moss |
Cypress Tree |
|
|
|
3. Braconid Wasp & Hornworm
A tiny wasp lays eggs inside a caterpillar. When wasp larvae hatch, they consume the caterpillar's body fluid and organs from the inside, slowly weakening and killing it.
|
Wasp Larvae |
Hornworm |
|
|
|
4. Dandelions & Lawn Grass
Dandelions and Kentucky bluegrass grow in the same sunny lawn. Their roots struggle for the same soil water and nitrogen, and both cast shade that blocks each other's sunlight.
|
Dandelion |
Lawn Grass |
|
|
ILEARN Biology Diagnostic Series • IAS B.3.1 / HS-LS2-6 STOP • End of Assessment Page 5 of 5
