1.Energy flows through (lost as heat); matter cycles
2.Pyramids can be disrupted by invasives, disease, or climate
3.Energy Pyramid: Only about 10% of energy transfers from one trophic level to the next, with the rest lost as heat. This explains why biomass and organism numbers decrease at higher trophic levels, creating the characteristic pyramid shape.
[!] STUDY GUIDE: Big Ideas
Use to answer form questions!
1.Only ~10% of energy transfers to the next trophic level.
90% is lost to heat, movement, and waste.
2.Biomass decreases at higher trophic levels. Less
energy available = fewer organisms.
3.Energy flows one direction; matter cycles.
Critical distinction: energy is NOT recycled.
Apex Predators (0.1%)
Secondary Consumers (1%)
Primary Consumers (10%)
Producers (100%)
THE 10% RULE: Each level gets only 10% of energy from level below
[#] KEY TERMS
Define in YOUR words
Trophic level
Position in food chain
10% rule
Energy transfer efficiency
Biomass
Total mass of organisms
Energy pyramid
Shows energy at each level
[?] THE PHENOMENON
Write BEFORE Hook form
Why are there more plants than animals in most ecosystems?
In the Serengeti, there are millions of grass plants, thousands of
zebras and wildebeest, but only a few hundred lions. This pattern
repeats in every ecosystem on Earth.
Your initial thinking:
[>] AFTER HOOK FORM
Reflect, then continue+2 pts
I learned that...
Station 1 — Energy Transfer
Energy is lost at each level because...
The 10% rule means...
Key insight:
Station 2 — Biomass Pyramids
Biomass decreases upward because...
Predators are rare because...
Key insight:
[/] DAY 1 EXIT TICKET
Complete before leaving+5 pts
Q1:
Which organisms are most abundant in the Serengeti? Why?
Q2:
From C3: How does natural selection create energy-efficient
organisms?
Confidence:
Energy Pyramids & Trophic Levels (continued)ANSWER KEY
Name:
[=]Day 2 start
Station 3 — Ecosystem Applications
If producers capture 10,000 J...
Apex predators need large territories because...
The 10% rule explains why...
Key insight:
[+] MAKING CONNECTIONS
Use for Exit Ticket!
How does natural selection from C3 relate to the 10% rule? (Hint:
Energy as selection pressure)
How will the 10% rule help explain ecosystem disruptions in W2?
[/] DAY 2 EXIT TICKET
Final check before Science Circle+5 pts
Q1 (NEW):
If producers capture 10,000 J of energy, calculate how much energy
reaches tertiary consumers.
Q2 (SPIRAL):
Explain why there are more plants than predators in terms of energy
AND biomass.
Q3 (INTEGRATION):
How does the 10% rule create selection pressure for energy
efficiency in organisms?
CHECKTEST YOUR THINKINGRate each: FALSE ← 1–2–3–4–5 → TRUE
1. Energy is recycled through ecosystems just like matter is.
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2. Only about 10% of energy passes from one trophic level to the next.
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3. Producers (plants) always have the most total energy in an ecosystem.
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4. Consumers create their own energy by eating food.
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5. Energy pyramids are always stable and never change shape.
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Pick any TWO statements — especially any you rated 2, 3, or 4. Justify your rating with evidence:
Statement #___ — I rated it ___ because:
Statement #___ — I rated it ___ because:
[O] SCIENCE CIRCLE
~15 min | End of week+3 pts
[!] My "Aha!" Moment
[?] My Remaining Question
Discussion Protocol: Share ahas, listen actively,
record class discoveries.