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Grade 9 · unit review

Review: Photosynthesis and Cellular Respiration

Trace matter and energy through biological chemical processes.

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Bring the unit skills together

Use these 4 new cases to check your reasoning. Choices are temporary and are not saved to an account, sent to staff or recorded as school grades. Download your current review choices before leaving or reloading.

Unit review questions
1. Which scientific label fits the specifically described step or feature? Supplied case: Air carbon becomes part of sugar.
Need a hint?
  • Look for the described feature: carbon input in the overall model.
  • Compare the given mechanism with the other labels; do not infer unmentioned events.
2. Which scientific label fits the specifically described step or feature? Supplied case: Fuel contains stored chemical energy.
Need a hint?
  • Look for the described feature: glucose used in simplified model.
  • Compare the given mechanism with the other labels; do not infer unmentioned events.
3. Supplied case 5: modeled glucose-molecule count=6, using the explicitly named quantities. Carbon-dioxide molecules required equal six times modeled glucose molecules. What result follows?
Need a hint?
  • Carbon-dioxide molecules required equal six times modeled glucose molecules.
  • Do not infer a direct one-step mechanism.
4. Which scientific label fits the specifically described step or feature? Supplied case: Same carbon atoms can enter new molecules.
Need a hint?
  • Look for the described feature: atoms move among chemical forms.
  • Compare the given mechanism with the other labels; do not infer unmentioned events.

The download contains your current choices and any checked feedback. Keep the separate transfer-task work in your own document; downloading its instructions does not mark it complete.

Use the skills in a new task

Create a four-panel explanation for “Photosynthesis and Cellular Respiration” using one supplied case from each lesson. Include the observation, scientific mechanism or calculation, result and a limitation. You may draw and speak your explanation; all inputs are supplied.

Work on paper or in your own document. Explain the choices you made.

  • Use one supplied case from each of the four lessons.
  • Name the relevant structure, quantity or process in every panel.
  • Show calculations with units or a causal evidence chain.
  • Distinguish source facts from fictional classroom data.
  • State a model limit or a condition that would change the result.
Compare with a model response

Panel 1: A plant model gains dry carbon-containing biomass while taking up CO₂. What source contributes that carbon? Which inference or prediction is best supported? Result: Atmospheric CO₂ can supply carbon incorporated into sugars.. Reasoning: Photosynthesis incorporates carbon while using energy; soil minerals do not supply all biomass carbon. Model limitation: only the stated classroom boundary and supplied observations are established; unmeasured real-world performance remains unverified. Panel 2: A dark plant model retains sugar, oxygen and functional respiration pathways. What can continue? Which inference or prediction is best supported? Result: Aerobic respiration can continue without current light capture.. Reasoning: Respiration uses available organic fuel and oxygen; photosynthesis has different requirements. Model limitation: only the stated classroom boundary and supplied observations are established; unmeasured real-world performance remains unverified. Panel 3: Supplied case 1: modeled glucose-molecule count=2, using the explicitly named quantities. Carbon-dioxide molecules required equal six times modeled glucose molecules. What result follows? Result: 12 CO₂ molecules. Reasoning: Substitute the supplied values: 6*(2) = 12 CO₂ molecules. Count six carbon atoms per glucose. This ratio alone omits water, oxygen and energy details. Model limitation: only the stated classroom boundary and supplied observations are established; unmeasured real-world performance remains unverified. Panel 4: The same carbon atom moves from CO₂ to sugar and back to CO₂. What is conserved? Which inference or prediction is best supported? Result: The carbon atom persists through rearranged molecules.. Reasoning: Matter cycles through forms; energy input and dispersal require separate accounting. Model limitation: only the stated classroom boundary and supplied observations are established; unmeasured real-world performance remains unverified.

A different response can also meet the criteria. Compare the evidence and reasoning, rather than copying the wording.