How do plants make food?
Plants make their food in a process which is called photosynthesis.
Photosynthesis requires sunlight, water and carbon dioxide.
Plants need water to obtain the nutrients that they need from the soil, and to transport them all around the plant.
Water is vital for a plant to live and to grow healthily.
Watch: How plants make food
Learn how the roots and stem carry water.
From trees to dandelions, most plants have roots and a stem.
Roots act like an anchor in the soil. They keep the plant in place and make sure it doesn’t fall over.
The bigger the plant, the deeper the roots go in the soil.
Soil is packed with all sorts of nutrients; the good stuff that a plant needs to survive like water and minerals.
Tiny hairs on the roots act like straws, sucking up all of the nutrients.
The roots can either store nutrients for later, or these goodies will be sent around the plant through thin tubes in the stem.
The plant’s leaves make food in a process called photosynthesis.
More tubes in the stem carry this food around the rest of the plant. All stems give a plant support.
A tree’s stem is made of wood while a dandelion’s is soft and bendy, but both help a plant grow up and towards the sunlight.
Fabulous plant facts
Almost all plant life on Earth depends upon photosynthesis for food.
A leaf usually has a large surface area, so that it can absorb a lot of light.
The water needed for photosynthesis is absorbed through the roots and transported through tubes to the leaves.
Some plants, like cacti, can store water in their stems to help them grow in dry, hot desert climates.
The largest tree in the world is the giant sequoia which can grow up to 90 metres in height. A sequoia needs between 2000-3500 litres of water a day in the summer.
Some plants that live in pond habitats, like the white water-lily, have their roots in water rather than soil.
Human-made plant food contains minerals such as nitrates, phosphates and potassium compounds.
Water's journey through the plant
Plants take water from the soil through their roots, but how does the water travel all the way to the leaves so that the plant can use it to make food?
Image caption, Roots
Roots are long thin tubes that are covered in tiny hairs. The roots act like little straws that suck water into the plant, and the hairs are like sponges that soak up as much water as the plant needs, and helps it travel through the roots and into the stem.
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Did you know?
Most plants need more water in hot weather, just like people do.
The leaves and stems of many desert plants have a thick, waxy covering.
This keeps the plants cool under the hot desert Sun and reduces water loss through evaporation.
Important words
Leaves – The parts of a plant that grow off the stem in order to take in sunlight.
Nutrients – Plants use minerals from the soil to survive and grow.
Photosynthesis – The process that plants use to transform energy from the Sun into food to help them grow.
Roots – The part of a plant that lives underneath soil or water. Roots are used to gather water and nutrients.
Stem – The main body of a plant.
Water – All plants need water to grow and survive.
Activities
Activity 1 – Plants and water quiz
Activity 2 – Grow a bean
You will need:
- a bean
- paper towels
- a tall glass
- water
- Take a tall glass and wrap some paper towels into a cylinder and place inside.
- Fill up the bottom quarter of the glass with water.
- Place a bean between the paper towels and the inside of the glass.
- Make sure it is above the water and doesn’t fall into it.
- Put it on a windowsill for a week or so. You should see the roots with their tiny hairs growing downwards and the shoot growing upwards.
Activity 3 – Plants and water activity sheet
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