What are the three things a plant needs for photosynthesis?

A plant needs sunlight, water and carbon dioxide. Sunlight provides the energy, water is absorbed through the roots, and carbon dioxide is taken in from the air through the leaves.

Why are most leaves green?

Leaves are green because they contain chlorophyll, a green pigment that absorbs energy from sunlight. This trapped energy powers photosynthesis, so the green colour is a sign the leaf is busy making food.

What does photosynthesis produce?

Photosynthesis produces glucose (a sugar the plant uses as food to grow) and oxygen. The oxygen is released into the air, which is why plants help supply the oxygen that animals and people breathe.

Does more sunlight mean a plant makes more food?

Generally yes — up to a point. More sunlight gives the leaf more energy, so it can make more sugar and release more oxygen, which is why most plants grow better in bright, sunny spots than in deep shade.

How is photosynthesis different from how animals get food?

Animals must eat other living things to get energy, but plants make their own food from sunlight, water and carbon dioxide. This is why plants are called producers and animals are called consumers.

How Plants Make Food: Photosynthesis

Science Interactive lesson Free to play

Photosynthesis is the process green plants use to make their own food, turning sunlight, water and carbon dioxide into sugar and oxygen inside their leaves. Unlike animals, plants do not eat — they build the energy they need from scratch, which is why they are called producers at the base of almost every food chain.

The process happens in chlorophyll, the green pigment packed into tiny structures in a leaf. Chlorophyll captures energy from sunlight and uses it to combine water drawn up from the roots with carbon dioxide taken in from the air. The result is glucose (sugar), which the plant uses to grow, and oxygen, which is released back into the air for animals and people to breathe.

Learning photosynthesis helps a child understand why plants need light, water and air, why leaves are green, and how plants quietly supply the food and oxygen that almost all living things depend on. It is a core topic in the Singapore primary Science syllabus on plant systems and survival.

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What this Spark covers

Meet the green chef

🌱 How Plants Make Their Own Food Plants can't go to the shop or open the fridge. So how do they eat? They make their own food — right inside their green leaves! The big science word for this is photosynthesis.Say it: foh-toh-SIN-thuh-sis 🗣️ Tap Next to find out the magic recipe!
The 3 ingredients

🧪 Three things the plant needs Just like a recipe, photosynthesis needs ingredients. Tap each card to peek inside! ☀️Sunlight Energy from the Sun powers the whole recipe. 💧Water Pulled up from the soil through the roots. 🌬️Carbon dioxide A gas from the air we breathe out. Peek inside all three cards to continue exploring.
The leaf is a kitchen

🟢 Why leaves are green Inside every leaf are millions of tiny green dots called chlorophyll. This green stuff catches the Sun's energy — it's the chef of the kitchen! Tap the leaf to wake up the green chefs!
Build the recipe

🧺 Feed the leaf! Drag each ingredient into the leaf to start cooking. Try them all! ☀️ Sunlight 💧 Water 🌬️ Carbon dioxide 🍪 Cookie 🍃 Drop ingredients here ☀️ 💧 🌬️ Hint: a plant can't eat snacks — it only uses sunlight, water and air!
More sun, more food

🔆 Turn up the Sun The more sunlight a leaf gets, the more food it can make. Slide the Sun and watch! Food made: 20% Oxygen out: • Try sliding all the way up to full sunshine. ☀️
What goes in, what comes out

♻️ In and out Photosynthesis takes things in and gives things out. Drag each card to the right basket! ☀️ Sunlight 💧 Water 🌬️ Carbon dioxide 🍬 Sugar (food) 🫧 Oxygen ⬇️ Goes IN ⬆️ Comes OUT Tip: the plant makes sugar and oxygen — those come out!
You're a photosynthesis pro!

🎉 Well done! 🌻 You now know how plants make their own food! ☀️ Sunlight + 💧 Water + 🌬️ Carbon dioxide ⬇️ inside the green leaf ⬇️ 🍬 Sugar (food) + 🫧 Oxygen Remember the big ideas: 🌿 Green leaves are the kitchen 🟢 Chlorophyll is the chef ☀️ Sun gives the energy 🫧 Oxygen is the gift for us! Next time you sit under a tree, say thank you — its leaves are making the air you breathe. 🌳💚

Frequently asked questions

What are the three things a plant needs for photosynthesis?: A plant needs sunlight, water and carbon dioxide. Sunlight provides the energy, water is absorbed through the roots, and carbon dioxide is taken in from the air through the leaves.
Why are most leaves green?: Leaves are green because they contain chlorophyll, a green pigment that absorbs energy from sunlight. This trapped energy powers photosynthesis, so the green colour is a sign the leaf is busy making food.
What does photosynthesis produce?: Photosynthesis produces glucose (a sugar the plant uses as food to grow) and oxygen. The oxygen is released into the air, which is why plants help supply the oxygen that animals and people breathe.
Does more sunlight mean a plant makes more food?: Generally yes — up to a point. More sunlight gives the leaf more energy, so it can make more sugar and release more oxygen, which is why most plants grow better in bright, sunny spots than in deep shade.
How is photosynthesis different from how animals get food?: Animals must eat other living things to get energy, but plants make their own food from sunlight, water and carbon dioxide. This is why plants are called producers and animals are called consumers.

How Plants Make Food: Photosynthesis

What this Spark covers

Frequently asked questions

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