Sun and Shade Lesson Plan

 

Overview

 

In this lesson, students will explore the ways that plants adapt to their environments.  Specifically, students will examine plants that thrive in the shade, versus plants that thrive in direct sunlight.  Special attention is devoted to the shape of leaves on respective sun and shade plants, and what those leaves tell us about the environments of the plants. This lesson can be used as a foundational lesson for later explorations that study plant and animal ecology and, in particular, the “green-up” and “brown down” of the earth.

 

Suggested Lesson Sequence	Please see the Earth Systems Foundations - Plants and Soils module description.
Level	Entry
Science Connections (Keywords in BOLD)	·        Students will investigate how plants are adapted to the environment. ·     Students will investigate how the shapes of leaves help plants survive in different conditions.
Math Connections	·     Students will learn that the size of a leaf is often related to the amount of sunlight the plant receives.
	·        Assessment and Standards Table (Word) ·        Assessment Activity Description (below) ·        Authentic Assessments (below)

 

 

Materials

 

• This lesson requires Adobe Reader.

• Plants in the Sun Activity Sheet (PDF)
• Plants in the Shade Activity Sheet (PDF)
• Sun or Shade? Activity Sheet (PDF)
• Sunny-Shady Drawing Activity Sheet (PDF)

 

 

Procedure

 

This lesson introduces the notion that plants adapt to their surroundings, and that leaves play an important role in these adaptations. Students will study the leaves found in sunny and shady environments. 

 

I.                Assessing Prior Knowledge

 

You may wish to begin your assessment of students’ prior knowledge by asking about the relationship between plants and the sun.

• Do plants need the sun?
• Do all plants need the same amount of sun to grow?  Examples?
• Are desert plants different from forest plants?

 

II.  Contextual Preparation

 

Teacher Information, Procedures, and Discussion Topics: 

 

Using your assessment of students’ prior knowledge, engage students in further discussion about plants.  To start out, you may wish to discuss climates – what kind of weather should plants on the playground be ready to withstand throughout the year?  What is it like for a plant in your back yard in January?  In July?  Do trees in your neighborhood look different in the winter and summer? 

 

This discussion can flow into the primary goal of this lesson – to examine the characteristics of leaves that grow on shade plants, and leaves that grow on plants that thrive in direct sunlight. Students may be curious to know that leaves are essential for plant survival – almost all plants have leaves of one type or another.  (Pine needles are leaves!)  You may wish to discuss that sunlight provides energy for plants, and that leaves are what “absorb” this energy for the plants from the sun.  The bigger the leaves are, the more sunlight they will absorb. 

 

To help motivate these points of consideration, have students bring leaves in from the playground that they collect during recess.  Help the students identify the type of tree/plant from which each leaf came, and how much direct sunlight that particular plant receives on a given day. 

 

Other possible discussion topics:

 

·     Do all plants can grow equally well in both sunny and shady environments?  

·     Will it be easier to absorb sunlight in a sunny or shady area? 

·     Have you ever gotten a sunburn?  When/how did that happen?  How do you prevent getting a sunburn?  How might plants prevent a “sunburn?”

 

III.  Student Activities

 

1.  Distribute the Plants in the Sun activity sheet. On this activity sheet, students will study the size and orientation of the leaves found in sunny climates.   Leaves found in sunny climates like the desert are generally oriented (pointed) toward the sun, and are small.  This helps the plant reduce exposure to the sun to minimize water loss from transpiration (the loss of plant water through leaves), while still capturing enough sunlight to survive.  Students examine several pictures of the leaves on sun plants, including modified leaves like cactus spines. 

 

Plants in the Sun discussion questions

 

What do sun plants look like?

What are the characteristics of leaves on sun plants?

What might happen to a desert plant that had very large, flat leaves?

 

2.  Distribute the Plants in the Shade activity sheet. Students will again study the size and orientation of the leaves.  The pictures of plants in this activity are found in the understory, or bottom of the rainforest.  These bottom leaves receive only roughly about 2% of the sunlight that leaves at the top of the rainforest get.  The understory leaves must be broad and flat to capture as much sunlight as possible.  Students will study pictures of several broad leaf plants.   Teachers may wish to share the following with students before engaging in the activity:

 

“The pictures of the plants on these pages are found in the understory of the rainforest.  The understory is found at the bottom of a forest.  In a thick forest, these leaves only get a small amount of sunlight because there are many other plants above them that block the sunlight.  The pictures in this activity sheet are of plants that grow in the shady understory of a rainforest.”

 

Shade plant discussion questions:

 

What do plants in the shade look like?

Which way do their leaves usually point?  Why do you think the leaves are pointed in that direction? (hint: remember that leaves are trying to capture enough sunlight for the plant to survive.)

Describe the shape and size of the leaves.  Why do you think the leaves look like that?

 

3.  Distribute the Sun or Shade activity sheet.  (This can also be used as an assessment task.)  For this activity, students use their knowledge to decide whether or not leaves pictured are likely to be from sun or shade plants.

 

 

IV.  Assessment

 

Check for students’ understanding about the relationship between available sunlight, and leaf size.  Distribute the Sunny-Shady Draw activity sheet.  Students are asked to draw a picture of either a sun plant or a shade plant.  Look for the orientation and size of the leaves they draw as an indicator of their understanding of the content of this lesson.  Students can either write or discuss their drawings with peers or in front of the class. 

 

Final assessment questions might include:

 

• Is it difficult for plants in the shade to receive sunlight? 
• Is it difficult for plants in the sun to receive sunlight?
• What do you think would happen if someone put a plant with very small leaves in the understory of the rainforest?  Would it get enough sunlight?  It is likely that such a plant would not receive enough sunlight to be able to survive or compete against other plants that are better adapted for shady environments.
• How are the leaves of sun plants different than leaves of shade plants?

 

 

Lesson Extensions for Authentic Assessment

 

Students will enjoy a plant scavenger hunt on the playground.  They might be encouraged to search for examples of both sun and shade plants on the playground.  Additionally, students may wish to measure the temperature differences in the immediate environments of the sun and shade plants they find. 

 

 

Acknowledgement

 

We gratefully acknowledge Celio Haddad, Gerald and Buff Corsi, Dr. Robert Thomas, and Margaret Orr for the photographs used in this lesson.