## Of a PianT come from

# Real-World Question-

An enormous oak tree starts out as a tiny acorn. The acorn sprouts in dark, moist soil. Roots grow down through the soil. Its stem and leaves grow up toward the light and air. Year after year, the tree grows taller, its trunk grows thicker, and its roots grow deeper. It becomes a towering oak that produces thousands of acorns of its own. An oak tree has much more mass than an acorn. Where does this mass come from? The soil? The air? In this activity, you'll find out by conducting an experiment with radish plants. Does all of the matter in a radish plant come from the soil?

Gerald and Buff Corsi/Visuals Unlimited

g sc f> Procedure-

1. Copy the data table into your Science Journal.

2. Fill the cup with dry soil.

3. Find the mass of the cup of soil and record this value in your data table.

4. Moisten the soil in the cup. Plant four radish seeds 2 cm deep in the soil. Space the seeds an equal distance apart. Wash your hands.

5. Add water to keep the soil barely moist as the seeds sprout and grow.

6. When the plants have developed four to six true leaves, usually after two to three weeks, carefully remove the plants from the soil. Gently brush the soil off the roots. Make sure all the soil remains in the cup.

7. Spread the plants out on a paper towel. Place the plants and the cup of soil in a warm area to dry out.

8. When the plants are dry, measure their mass and record this value in your data table. Write this number with a plus sign in the Gain or Loss column.

9. When the soil is dry, find the mass of the cup of soil. Record this value in your data table. Subtract the End mass from the Start mass and record this number with a minus sign in the Gain or Loss column.

 Mass of Soil and Radish Plants Mass of dry soil and cup Start Do n End ot write ii 1 this book. Mass of dried radish plants 0 g