Key Idea: The process of photosynthesis converts light energy to stored chemical energy by converting carbon dioxide plus water into sugars plus released oxygen.
Students are expected to know that:
- The reactants of photosynthesis are carbon dioxide molecules and water molecules and the products are glucose molecules and oxygen molecules.
- During photosynthesis bonds are broken between atoms of carbon dioxide molecules and water molecules and new bonds form to produce glucose molecules and oxygen molecules.
- The process of photosynthesis requires energy because the energy required to break bonds between carbon dioxide molecules and water molecules is more than the energy released when bonds form to make glucose and oxygen molecules.
- Light transfers the energy required for photosynthesis from the sun to plants.
Boundaries:
- Students are not expected to know that photosynthesis involves two processes: (a) light- dependent reactions in which light drives the synthesis of ATP (and
NADPH) and (b) carbon-fixation reactions in which reactions involving ATP (and NADPH) drive the formation of carbon-based molecules from CO2.
| Item ID Number |
Knowledge Being Assessed | Pre-Test | Post-Test | Select This Item for My Item Bank |
|---|---|---|---|---|
The reactants of photosynthesis have less energy than the products. | 28% | 56% |
|
|
Plants use carbon dioxide and water to make glucose and oxygen. | 28% | 52% |
|
|
21% | 36% |
|
Misconception |
Student Misconception |
Pre-Test | Post-Test |
|---|---|---|---|
Energy is released during photosynthesis (Chabalengula et al., 2012; Sanders, 1993). | 34% | 21% | |
26% | 28% | ||
Energy is neither released nor absorbed during a chemical reaction. | 23% | 13% | |
19% | 25% |
Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.
Code |
Statement |
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