dcf.cymru stimulus sheet · Science · Year 8
Making a photosynthesis video
Ysgol Gynradd Nant Celyn, its request and Gethin’s storyboard are invented for practice. The science on the fact sheet is accurate for Key Stage 3.
1. The brief
The Year 6 teacher at Ysgol Gynradd Nant Celyn wants a 60 to 90 second explainer video on photosynthesis for her class. It will go on the school website, and many families watch on phones, often with the sound off. The video must show the word equation, where photosynthesis happens, how leaves are adapted, what the plant does with the glucose, and that plants respire all the time.
2. Fact sheet
- Photosynthesis is how a plant makes its own food. It happens in the chloroplasts, mostly in the palisade cells near the top of the leaf. Chloroplasts contain chlorophyll, a green substance that absorbs light energy.
light energy
carbon dioxide + water --------------> glucose + oxygen
chlorophyll
- Carbon dioxide diffuses from the air into the leaf through tiny pores called stomata, mostly on the underside. Oxygen and water vapour diffuse out the same way.
- Water is absorbed from the soil by the roots and carried up the stem to the leaves.
- Leaves are adapted: broad, giving a large surface to absorb light; thin, so gases only diffuse a short distance; stomata let gases in and out; palisade cells are packed with chloroplasts.
- Glucose is used for respiration, which releases energy. Spare glucose is stored as starch (in leaves, seeds and potatoes) or made into cellulose for cell walls.
- Plants respire all the time, day and night. They photosynthesise only in the light.
- Plants do not breathe: breathing is muscles moving air in and out of lungs. Gases enter and leave a leaf by diffusion. Plants do not get food from the soil: they make it. The soil gives water and minerals.
Word bank
photosynthesis · chlorophyll · chloroplast · palisade cell · carbon dioxide · oxygen · glucose · starch · cellulose · respiration · diffusion · absorb · stomata (one is a stoma)
Spelling tips: photosynthesis; chlorophyll and chloroplast (both start chloro, Greek for green); respiration comes from respire.
3. Gethin’s first storyboard
| Frame | Sketch and shot | Narration | Caption | Time |
|---|
| 1 | Wide shot: an oak tree (picture copied from Google Images) | Hi everyone! Today we are learning about photosinthesis. It is how plants make there food. | How plants make food (yellow letters on the white sky) | 4 s |
| 2 | Close-up: roots in soil, with arrows | Plants breathe in carbon dioxide from the air. The roots takes in water from the soil. | CO2 in, water in | 5 s |
| 3 | Extreme close-up: a leaf with green dots | Inside the leaf the clorophyll is kept in tiny cloroplasts. The stomata is green and soaks up the light from the Sun. | Chlorophyll | 5 s |
| 4 | Diagram on a whiteboard | The plant uses the light energy to turn carbon dioxide and water into glucose, which is a sugar. Then it gives out carbon dioxide into the air for us to breathe. | Carbon dioxide and water are turned into glucose and oxygen using light energy that is absorbed by the chlorophyll in the leaf | 4 s |
| 5 | A potato and a runner | The plant used some of the glucose for resperation. It stores the rest as starch, for example in potatoes. Plants only respire at night when the Sun has gone down. | Glucose: used for energy | 5 s |
| 6 | A leaf | The leafs is broad and thin so they can get lots of light. Thanks for watching! | THE END | 3 s |
Gethin’s note: “Total 26 seconds. Music: my favourite pop song in the background.”
4. Video design guidance
- Shot types: wide shot (the whole scene), close-up (one object), extreme close-up (a small detail), diagram or animation, title card (text only).
- Narration: people speak clearly at 2 to 3 words per second. Plan with 2.5, and add a 1 second pause when the frame changes.
- On-screen captions: 8 words or fewer, a large plain font readable on a phone, on screen for at least 3 seconds.
- Contrast: dark text on a light background or light on dark. Avoid yellow on white, and red on green, which many colour-blind viewers cannot tell apart.
- Closed captions (subtitles): the narration word for word, for viewers who are deaf, hard of hearing or watching with the sound off.
- Images and music: use your own drawings and photos, or ones whose licence allows reuse (for example Creative Commons). Never copy from an image search. Most pop songs are protected by copyright.
- Credits card: end with who made the video, where each image and sound came from, and its licence.