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S1 Science: Plants and Photosynthesis (Paper 1 (basics))
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Tutor Prep Guide · Photosynthesis inputs and outputs, leaf structure, stomata and transpiration, and the iodine starch test
S1 Science: Plants and Photosynthesis (Paper 1 (basics))
This paper covers the basic inputs, outputs and the place of chlorophyll, checked with molecule counts.
Direct answers Photosynthesis takes in carbon dioxide and water and gives glucose and oxygen, all inside the chloroplast.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 20 |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1 |
| Chapter | Chapter: S1 Science: Plants and Photosynthesis |
| Level | S1 |
02 Questions (10 items)
- FoundationWhich process do plants use to turn water and carbon dioxide into food?
- FoundationWhich three things does photosynthesis need?
- FoundationWhich gas is released by photosynthesis?
- IntermediateInside which structure of the cell is chlorophyll found?
- IntermediateIf 6 molecules of carbon dioxide take part in photosynthesis, how many molecules of water are needed?
- IntermediateHow many molecules of glucose can 12 molecules of carbon dioxide make at most?
- ChallengeIf 18 molecules of water are used, how many glucose molecules form and how much oxygen is released?
- ChallengeA plant has 5 leaves of 12 cm2 each. If every 10 cm2 releases 3 cm3 of oxygen per hour, how much does the whole plant release in half an hour?
- ChallengeAt which time of day is the rate of photosynthesis greater than the rate of respiration?
- Error redoA student says the food of a plant is sucked straight out of the soil. What is wrong?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | Photosynthesis | Photosynthesis takes place in chlorophyll and stores light energy as chemical energy in glucose. |
| 2 | Light, carbon dioxide and water, together with chlorophyll | If any one of them is missing the rate falls or the process stops. |
| 3 | Oxygen | The oxygen comes from split water and leaves through the stomata. |
| 4 | The chloroplast | Palisade cells hold many chloroplasts, and that is where photosynthesis happens. |
| 5 | 6 molecules | The equation 6CO2 + 6H2O gives C6H12O6 + 6O2, so the two sides balance. |
| 6 | 2 molecules | Six molecules of carbon dioxide make one glucose, so 12 divided by 6 gives 2. |
| 7 | 3 glucose molecules and 18 oxygen molecules | Every 6 water molecules give 1 glucose and 6 oxygen, and 18 divided by 6 is 3. |
| 8 | 9 cm3 | The total area is 60 cm2, giving 18 cm3 per hour, so half an hour gives 9 cm3. |
| 9 | During the hours when light falls on the plant, that is daytime | In light the plant takes in more carbon dioxide than respiration releases. |
| 10 | The soil supplies only water and minerals, while the food is made in the leaves by photosynthesis | This is a common mistake: taking up water is confused with taking up food. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
For photosynthesis questions ask three things: whether all inputs are present (light, carbon dioxide, water), what the outputs are, and which condition the experiment changed.Tutor Registration →
Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.