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| Question | Answer |
| What does a plant need to photosynthesise? | Carbon dioxide, water, light, and chlorophyll -which needs magnesium ions. |
| Why would a plant need a healthy root system to photosynthesise? | To photosynthesise, plants need chlorophyll and water. But to make chlorophyll, you need magnesium ions, so roots are used to get these ions and water which are vital for photosynthesis. |
| When and why would plants carry out the reversal of photosynthesis. | This reversal is called respiration, it happens all throughout the day, especially at night. As there is no light at night, there is no energy for photosynthesis. Plants use this time to release energy from food to function - ie they respire |
| Why is clearing large amounts of forest areas worrying scientists? | The trees take in carbon dioxide, and release oxygen. |
| Why do plants look green? | The pigment - chlorophyll is green, it is in chloroplasts which are on the upper layer of the leaf. The layer above them is transparent. So the visible green chloroplasts reflects the green light making it look green. |
| In which direction does the water in the xylem travel? | It travels upwards as it progresses from the roots, to the stem and veins. |
| Where in the cells does photosynthesis occur? | In the chloroplasts |
| Why is excess sugar often stored as starch and not simple sugar? | Simple sugar can dissolve in water, and the plant would not be able to return the sugar. But starch is insoluable so it can be easily stored. |
| Why are leaves often arranged so they do not shade each other? | So that each leaf can recieve light. |
| What substances are made with photosynthesis? | Glucose and oxygen. |