Life Support for Plants

Basic Needs of Plants Air Nutrients Water Soil

Why do plants need air? There is carbon dioxide in the air. Leaves take in this carbon dioxide. Carbon dioxide is one of the two main materials plants use to make food.

Why do plants need nutrients? Just as animals need nutrients (vitamins and minerals) for growth, so do plants. Soil provides plants with the nutrients they need to survive. Plants cannot survive in soil that doesn’t have the necessary nutrients.

What about water? Plants get water from rain. Some of the water is absorbed through the plant leaves. Most is absorbed by the roots.

Necessary Light No plant can live in total darkness. Some plants, however, may grow better in shaded areas.

Photosynthesis Scientific name for the process by which a plant makes its own food “Photo” means “Light” “Synthesis” means “Putting Together” Plants make food from light energy combined with carbon dioxide and water.

How does photosynthesis work? Light + Carbon Dioxide + Water Light is trapped by the chlorophyll. Leaves take in carbon dioxide. Roots take in water. Water travels to leaves. In the leaves, sugar is formed. Oxygen is then released into the air by the leaves.

Plant Adaptations Water plants grow from soil below the water, with stems growing toward surface Vines grow on forest floors, but have stems climbing and clinging to other plants or objects for support and to get sunlight Desert plants have thick stems that can store water for long periods; also have roots near surface, to absorb water quickly