How do Plants Make Their Own Food?
You know, of course, that there are hundreds of
thousands of different plants in the world. How many kinds of
plants can you think of? There are trees, bushes, vegetables, flowers,
grasses, and many more. Even though there are such a variety of plants, all
of them have several things in common.
1
Plants have roots. Roots are very important parts of plants in many
ways. Roots absorb water and nutrients that plants need to grow. They also
can store that food. Some plants like radishes, carrots, and turnips store
their food in their roots. Roots also help to support plants.
2
Plants have stems. Stems move water and food from the plant's roots
to its leaves and flowers. They also support leaves and flowers. Some plants
use their stems for storage. Desert cacti store water and food in their
stems. You may think all stems are easy to see, like that of a tree. But some
stems stay underground. The potato you eat is an underground stem!
3
Plants have leaves. They can be very different in size from tiny
invisible leaves to some huge ones that you can see on palm trees. Leaves also
vary in color. Some of them are different shades of green, when the others
may not be green at all. The main job of all leaves is to expose green tissue
to the sun. Some of them also store food, hold water, and prevent water
loss.
4
What materials, or things, do plants use to make their food? Plants
use light, water and carbon dioxide to make their own food. The way plants
make food is called photosynthesis. This word means making food with light!
Photo means light and synthesis means putting together.
5
How does photosynthesis work? The plant gathers the materials it
needs to make food: The roots suck up water from the ground. The water
travels up the stem of the plant to the leaves. The small openings in the
underside of the leaves let carbon dioxide in. Sunlight is gathered through
the top of the leaves and trapped by a special plant chemical called
chlorophyll. Chlorophyll is green. Plants are green because they have
chlorophyll.
6
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The plant uses energy from the sun to "mix" the molecules of carbondioxide with the molecules of water. The atoms in the water and carbon
dioxide molecules get rearranged, or taken apart and put back together
differently, and change into one molecule of sugar, or glucose, and six
molecules of oxygen.
7
The plant stores the food, or sugar, in its stem, leaves and roots. The
plant "spits out" the oxygen it has made. People and animals breathe in the
oxygen from the air.
8
1. In paragraph 5, the word photosynthesis means –
to make light.
to make something.
the process in which plants make food.
carbon dioxide.
2. The main job of the leaves is to –
absorb water and nutrients.
move water and food through the plant.
expose green tissue to the sun so that it can make food.
take in oxygen from the air.
3. In paragraph 7, the word glucose means –
oxygen.
carbon dioxide.
sugar.
chlorophyll.
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4. The main job of the roots is to –
absorb water and nutrients.
move water and food through the plant.
expose green tissue to the sun so that it can make food.
take in oxygen from the air.
5. Use the chart to answer the question below.
1. The plant gathers the materials it needs
to make food.
2. The plant uses energy from the sun to
mix the molecules of water with the
molecules of carbon dioxide.
3.
4. The plant stores the food it has made in
its stem, leaves and roots and spits out the
oxygen it has made.
Which of these belongs in the empty box?
The plant releases the oxygen it has made.
The atoms in the molecules of carbon dioxide and water are
rearranged and change into new molecules of sugar and oxygen.
People and animals breathe in the oxygen from the air.
The small openings in the underside of the leaves let carbon
dioxide in.
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