This worksheet uses three fictional cases to compare two benefits, a benefit with an explicitly unaffected partner, and a benefit with missing evidence. Learners choose each partner's effect before selecting a classification. The HTML activity checks those choices and reveals sentence-specific reasoning while leaving written evidence explanations for teacher review.
Read the two effects separately
Use three codes: + for an explicitly stated benefit, 0 for an explicit statement that the partner is neither helped nor harmed, and Unknown when the card supplies no effect. These codes summarize the text. They are not measurements from an ecological experiment.
Under the definitions used here, mutualism benefits both species. Commensalism benefits one while leaving the other unaffected. OpenStax's community ecology chapter explains those distinctions. The worksheet's unnamed species and cards are original examples, separate from the textbook's organism cases.
Ask learners to copy or paraphrase the relevant detail for each partner. If the detail is absent, say that it is absent. A plausible story about how a species might benefit belongs in a hypothesis discussion, not in the supplied-evidence column.
Work through the three cards
M01 says species A receives shelter from B and B receives food from A. The effects are A + and B +. Both benefits are stated, so mutualism is supported. A response citing only A's shelter still needs B's food detail to complete the explanation.
M02 says species C receives food through its interaction with D, while D is explicitly neither helped nor harmed. The effects are C + and D 0. Commensalism is supported under the stated definition. The unaffected statement does work here; it is not an inference from a missing description.
M03 says E receives shelter through its interaction with F and gives no information about F's effect. E is + and F is Unknown. There is insufficient evidence to choose mutualism or commensalism. The next question is what effect the interaction has on F.
Keep all three complete cards available while learners compare them. The distinction between M02 and M03 is easiest to discuss when the explicit unaffected statement sits beside the absence of such a statement.
Attempt a row before opening the key
Each card offers separate choices for partner 1, partner 2, and classification. Blank choices remain unanswered. "Insufficient evidence" is a deliberate answer and must not be confused with leaving the classification empty.
After Check, feedback names the supplied benefit, unaffected statement, or missing detail. Changing a choice clears the old feedback so the learner can attempt the row again. The separate teacher key shows all three reasoning traces; it does not fill learner fields or grade a free-text explanation.
The Unknown cases filter shows M03 while keeping the other two cards and their temporary responses intact. Return to All cases to compare them again. Reset clears choices, explanations, feedback, and reveal state while preserving the original case text.
Plan the follow-up question
Ask for the missing effect before accepting a label. For M03, a learner can identify exactly what is needed without inventing an organism or mechanism. This short packet does not cover every ecological relationship or make a universal claim about all uses of "symbiosis."
Copy this prompt
Build one self-contained US-English HTML two-partner ecology worksheet. Use a field-notebook design with clearly separated partner columns, complete case text, large choice buttons, and a separate teacher key. All text is at least 16px and the layout stacks at 360px. No remote assets, collection, or saved responses.
Define + as stated benefit, 0 as explicitly neither helped nor harmed, and Unknown as missing effect evidence. Mutualism requires two benefits; commensalism requires one benefit and an explicitly unaffected partner. Unknown never becomes zero.
Use exact fictional cases: M01 A receives shelter from B; B receives food from A. M02 C receives food through interaction with D; D is explicitly neither helped nor harmed. M03 E receives shelter through interaction with F; no effect on F is supplied. Do not invent real organisms or mechanisms.
Each case starts with blank partner-effect choices, classification choices, and a labeled evidence explanation field. Use type=button choices and Check. Keys are M01 +/+/Mutualism; M02 +/0/Commensalism; M03 +/Unknown/Insufficient evidence. Feedback must point to both stated effects or the missing F effect. Explanations remain for teacher review, without semantic grading.
Include All cases and Unknown cases filters; Unknown shows M03 without deleting other attempts. Provide a separate revealable teacher key and Reset, which clears all learner fields, feedback, filters, and reveal state. Edits clear stale feedback. Keep intentional insufficient evidence distinct from unanswered. State that reload clears entries and native classroom records remain authoritative. Return complete responsive HTML with explicit selectors, accessible state labels, and visible keyboard focus.
Before class, choose which evidence detail learners will cite aloud for each partner. Preview the HTML cards and reasoning together in NOS if that helps prepare the discussion. Keep the printable worksheet and actual learner observations in your classroom records, and leave M03 open until evidence about F is supplied.