Photosynthesis
Four things a leaf needs to make food.
The leaf kitchen
A leaf prepares food for the whole plant. For this it needs some things to come together.
How many things do you think a leaf needs, all together, to make food?
What this lesson covers
The idea
Photosynthesis is the process by which plants prepare food in the presence of sunlight and chlorophyll; sunlight, water, chlorophyll and carbon dioxide are all essential for it.
The leaf kitchen
A leaf prepares food for the whole plant. For this it needs some things to come together.
How many things do you think a leaf needs, all together, to make food?
- Only one
- Two
- More than two
Switch them off
Switch each need off, one at a time. Then put all of them back on.
A name for it
The leaf made food only when all four were present. The process of preparing food in this way has a name: photosynthesis.
Photosynthesis is the process by which plants prepare food in the presence of sunlight and chlorophyll; sunlight, water, chlorophyll and carbon dioxide are all essential for it.
- Need | Where it comes from
- Sunlight | The Sun
- Water | Taken up by the roots
- Chlorophyll | The green pigment in the leaf
- Carbon dioxide | The air
Notes
Photosynthesis is the process by which plants prepare food in the presence of sunlight and chlorophyll; sunlight, water, chlorophyll and carbon dioxide are all essential for it.
Check yourself
What is photosynthesis?
Which of these is NOT needed for photosynthesis?
A plant has water, chlorophyll and carbon dioxide, but is kept in the dark. Will it prepare food by photosynthesis?
How many things are essential for photosynthesis: sunlight, water, chlorophyll and carbon dioxide?
Answer: 4 things
Four things: sunlight, water, chlorophyll and carbon dioxide.
- The way a plant eats other living things. Plants do not eat like animals. They prepare their own food.
- The way a plant takes up water from the soil. Roots take up water. Photosynthesis is how plants prepare food.
- The way a plant prepares food, using sunlight and chlorophyll — correct. Yes! It is how plants make their food.
- Iodine solution — correct. Yes! Iodine is only used to test for starch.
- Chlorophyll. Chlorophyll is essential for photosynthesis.
- Sunlight. Sunlight is essential for photosynthesis.
- Yes, three things are enough. All four things are essential. One missing thing stops it.
- No, because sunlight is missing — correct. Yes! All four are essential.
- Yes, water is the only thing needed. All four things are essential. Sunlight is missing.