1. STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds Kennewick School District

2. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
This is a hidden slide for teacher information.
Overview
In addition to growing in height, plants also develop leaves and flower buds. In this lesson, students will observe the first true leaves and the buds on their Brassica plants and record their observations in both words and pictures. These developments will take place on approximately Day 7, 8, or 9.

3. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
This is a hidden slide for teacher information.
Lesson Objectives
Students observe two major developments: the true leaves and the flower buds.
Students record their observations in their notebooks.
Students review the life cycle of a plant through this stage of development.

4. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
This is a hidden slide for teacher information.
Background
In the life cycle of the Brassica plant, the embryonic root is the first part to emerge from the seed, usually within 24 hours of planting. About 24 hours later, the two cotyledons (now called the seed leaves) appear above the ground, supported by the embryonic stem. The cotyledons, which were white while inside the seed, become green, and take on the job of producing food for the seedling until the true leaves develop. This takes place at about Day 7.
The seed leaves remain on the plant for some time after the true leaves have developed. Eventually most seed leaves will wither, die, and drop off. Right now, however, students can observe both kinds of leaves on the same plant. They will be able to see that the seed leaves are smooth and heart-shaped while the true leaves are larger, have wavy irregular edges, and a rougher texture.

5. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
This is a hidden slide for teacher information.
Background (cont.)
Soon after the true leaves appear, the buds develop. They appear at the top pf the stem in a cluster. The buds are closed tightly and are greenish-yellow in color. In another day or two, the buds will open to reveal the four-petaled, bright yellow Brassica flower.
This is a good opportunity to use the larger Life Cycle Cards (Appendix E) to review the growth and development of the plant up to this point. Figure 6-1 shows the Life Cycle Cards and explains each stage of development.

6. The Life Cycle of Fast Plants
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
This is a hidden slide for teacher information.
The Life Cycle of Fast Plants
Permission to use granted. Copyright by Wisconsin Fast Plants, University of Wisconsin-Madison. Illustrated by Amy Kelley.

7. Materials list For each student: Student notebook
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
Materials list
For each student:
Student notebook
1 quad of plants with buds
For every two students:
1 hand lens
For the class:
Life Cycle Cards 1, 2, 3, 4, 5, 6 (Appendix E)

8. Observe your quad of plants with a hand lens. Look for the following:
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
Observe your quad of plants with a hand lens. Look for the following:
Differences between the seed leaves and the true leaves
Number of both kinds of leaves
Color, size, shape, and number of buds

9. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
Draw and label the plant using a full sheet of paper. Your drawing should show the following:
today’s date
the age of your plant in days
the differences between the two kinds of leaves
the buds
the right number of leaves and buds

10. Write several descriptive sentences about your plant.
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
Write several descriptive sentences about your plant.
Hints on what to write:
Describe how the two kinds of leaves are different
Describe the size and shape of each kind of leaf.
Tell how the two kinds of leaves feel. But touch the leaves very carefully.
Describe the colors of the buds.

11. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
Clean up. Return your plant to the water mat and put the hand lenses away.

12. Update your Table of Contents
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
Update your Table of Contents

13. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
How old are the plants today? Our plants have changed a lot since Day 1. What was the first stage of the plant’s life cycle?

14. At about 24 hours after planting, the embryonic root emerges.
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
At about 24 hours after planting, the embryonic root emerges.

15. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
After about 28 hours, the seedling emerges from the potting mix. The seed coat is split and the white cotyledons or seed leaves are visible.

16. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
During Day 2 and 3, both the root system and the cotyledons, which are now green, continue to grow.

17. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
On Day 4 or 5, the first true leaves appear at the growing tip of the plant, between the seed leaves.

18. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
From Days 4 through 7, the true leaves continue to emerge and grow at a remarkably rapid pace.

19. By Day 8 or 9, the yellow-green flower buds appear in a tight cluster.
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
By Day 8 or 9, the yellow-green flower buds appear in a tight cluster.

20. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
What do you think will happen to the plants next? Write your predictions in your notebook.

21. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
Class Predictions

22. STC Plant Growth and Development
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
Add this vocabulary word and its meaning to your glossary.
true leaves
Larger leaves which develop after the seed leaves with wavy, irregular edges, and a rougher texture.

23. A flower that has not yet opened.
STC Plant Growth and Development Lesson 6: Observing: Leaves and Flower Buds
Add this vocabulary word and its meaning to your glossary.
flower buds
A flower that has not yet opened.