When a seed starts to grow it has the four parts you looked at earlier. The plant embryo puts down a root. It puts up a stem. A pumpkin sprout has seed leaves or cotyledons full of stored food. Then it makes pumpkin leaves. Sometimes a bug eats one of these parts. Let’s find out which parts a sprout must have to grow into a plant.
Question: Can a sprout become a plant if part of it is missing?
Step 1: Open your Science Journal, write “Investigation 6” and the date. Copy Table 1 into your journal. You will start your observations after doing Step 6.
Step 2: Label the Cups 1 to 4. Put potting soil in the cups and firm it. The top should be 1.5cm from the top of the cup. Add water so the soil is damp but not soggy.
Step 3: Push two pumpkin seeds into each cup until they are 2cm deep. The seed should be pushed in sideways.
Step 4: Cover the seeds with soil. Put the tray in a safe warm place. Water them if they get dry but don’t make them soggy. You can put plastic wrap over the tops to keep them from drying out.
Step 5: Check the cups everyday until the seeds germinate.
Step 6: Be very careful doing this part. You will use your thumbnail to pinch some part off six of the seedlings. The parts are very small and close together so it is easy to pinch off a part you don’t mean to. This is why you wait until after doing this part to number the Cups.
One Cup: Remove only the cotyledons and leave the growing tip.
Second Cup: Remove the growing tip but leave the cotyledons alone.
Third Cup: Remove both the growing tip and the cotyledons.
Fourth Cup: Leave these sprouts alone.
Step 7: Set the cups in a bright place but not in the sun. Water them if they get dry but don’t make them soggy.
Step 8: Check the sprouts every day to see how they grow until the sprouts you did not pinch anything off of have their first true leaves. Describe what the sprouts are doing in Table 1.
Describe the sprouts before you remove any parts
Predict what will happen to each of the sprouts after you remove part of them.
Describe how a pumpkin sprout comes out of the soil.
How does this protect the new seedling?
How well did your predictions match what happened?
Which parts are necessary for a pumpkin sprout to grow into a plant? Explain.