Middle School Life Science Quiz
20 questions · no time limit
0:00
ECOSYSTEMS: INTERACTIONS, ENERGY, AND DYNAMICS
Question 1 of 20
No time limit
Current
Answered
Flagged
Not seen
A lake has an invasive plant that blocks sunlight and lowers oxygen for fish. The community must choose ONE management plan.
Conservation choices:
- Option A: Introduce a non-native insect that eats the invasive plant.
- Option B: Mechanical removal (harvesting boats) twice each summer.
- Option C: Apply a chemical herbicide once each summer.
Criteria and evidence:
- Scientific: Mechanical removal reduces plant coverage by ~50% but regrows by next year. Herbicide reduces coverage by ~70% but may temporarily lower oxygen for 1–2 weeks. The insect reduces coverage by ~60% after 2 years but sometimes also feeds on a related native plant.
- Economic: Option A costs $40,000 upfront and $5,000/year monitoring. Option B costs $70,000/year. Option C costs $25,000/year.
- Social: Residents are concerned about chemicals; 65% oppose herbicide. Most residents support mechanical removal.
Constraints:
- The lake is a drinking-water source, so regulations allow herbicide only if it does not reduce oxygen below 4 mg/L.
- The town's budget is $60,000/year.
- The plan must show improvement within 1 year.
Which conservation choice is best justified by the evidence and constraints?
YOUR PROGRESS
20
QUESTIONS
Ready when you are
Answer in any order. Your progress shows here as you go.
QUESTIONS
KEYBOARD
Pick an answer ABCD
Next question ↵→
Previous ←
Flag for review F
Answers save as you go · flagged questions come back at the end