Mini-1
Subject / Course: Science / TC Name: Ms SayerGrade Level: Grade 1/6/7 / Date: 2011
Topic: Plant adaptations? / Duration of lesson: 50 minutes
1. Objectives and Skills
1. Investigate the how plant are adapted to their environments.
2. Investigate how Desert plants store and conserve water.
3. Investigate the different shapes of trees
4. Investigate how pine cones work.
2. Materials
-1. 1. Sponge (expanding type best, ordinary kitchen sponge will work)
-1. 2. Waxed paper
-1. 3. Toothpicks
-1. 4. Flashlight
-1. 5. 8 oz. plastic cups
-1. 6. Water.
-1. 7. Scissors
-1. 8. Scales (postage type will work)
9. Modeling clay
-1. 10. Newspaper
-1. 11. Two 6-by-10-inch (15-by-25-cm) pieces of poster board
-1. 12. Transparent tape
-1. 13. Spoon
-1. 14. Flour
-1. 15. Paint brush
-1. 16. Pine cones
-1. 17. Leaves
-1. 18. Scissors
-1. 19. Cardboard (cereal box cardboard works well)
-1. 20. Glue
-1. 21. Paper towel
-1. 22. Twine or thick thread (not pictured)
-1. 23. Red, yellow, orange, brown paint
-1. 24. Different types of leaves
-1.
3. Activities
Introduction
Ask the students what a plant needs to survive? Explain that a plant needs water, sun and soil with the younger students and discuss photosynthesis with the older students.
Explain to the students that we are going to look at how plants are adapted to their environments. Ask the students what they think adapted means? Explain to the students that an Adaptation is a structure or behavior that helps an organism survive in its environment (all the living and nonliving surroundings of an organism). One adaptation by coniferous plants to a short growing season in coniferous forests is their retention of leaves, which allows them to start photosynthesis as soon as temperatures permit in the spring, instead of having to spend time growing leaves. Another adaptation is the dark color of their leaves, which helps to absorb heat from sunlight.
Labs Procedure:
Part A: Leaf shape.
Show the students a series of different tree leaves (one succulent, one with gutters, one that’s broad and one with holes in it). Ask the students why there are some many different types of leaves?
Step 1:Trace the leaf patterns on the following pages so your students can use them.
Step 2: Have each group of students cut out a set of patterns in both construction and waxed paper. (You may also have hem use some large leaves found in your area as patterns.)
Step 3: Have students work first with the construction paper leaves. Mist each with water and observe which one sheds water best. Compare results. (The heart-shaped drip-tip, pleated
fan-shape, fern, and split-shaped leaves should do the best.)
Step 4: Repeat with wax paper leaves to compare with the construction paper ones. (The waxed coating should help leaves shed water.)
Step 5: Ask the students how leaves that shed water well might help plants in wet places survive? (Leaves which shed water and dry quickly would be less likely to mold or mildew or be settled by small plants.)
Step 6: Give each group one large and one small sponge. Have them put each sponge in a dish. Have students pour equal amounts of water over each sponge. Allow the sponges to sit in the water for a minute or so.
Step 7. Have students squeeze the thin sponge into a cup. How much did it hold? Repeat with the thicker sponge. Put the measuring cups next to each other. Which one has more water? (Older
children can subtract to measure how much more the thick
sponge holds.) Which sponge will dry out faster?
Step 8. Remind the class that some plants live in places with lots of water, while others live in places with very little water. Where would thick leaves be better? Thin leaves? Why? Thick leaves like thick sponges can hold a large amount of water. In places where rain falls infrequently, plants with thick, sponge-like succulent leaves survive the droughts.
Part A: Leaf coverings
Ask the students why some plans have waxy textures and why some leaves don’t?
Step 1: Wet three paper towels until they are saturated with water but not dripping.
Step 2: Put one of the paper towels flat on a cookie sheet.
Step 3: Roll up the second paper towel, paper clip it to keep it rolled up, and put it on the cookie sheet, too.
Step 4: Put the third paper towel on a piece of waxed paper that is the same size. Roll up the waxed paper and the paper towel together, and paper clip them so they stay rolled up.
Step 5: Leave all three paper towels where they are for 24 hours. Then check them. Here's what you'll find:
The flat one will be dry. The rolled one will be dry or mostly dry. But the paper towel that is rolled up with the waxed paper will still be wet.
Now, you may be asking, "What does this have to do with plants in the desert?"
Here's the answer: Cacti and other desert plants are like the paper towel that is rolled up with waxed paper. These plants have waxy coverings that keep moisture from evaporating into the dry desert air. That's part of the reason they can survive on the little water they get in the desert.
Also Since most water in coniferous forests is frozen during the winter, it is not available for plant roots to absorb it. Many evergreen trees, much like desert plants, are adapted to the scarce water supply because they have small leaves with a limited surface area and a waxy coating, which helps hold water in. Falling snow can collect on the limbs of trees with round or square crowns, causing the limbs to break. But the triangular shape of the crown of these trees and the needle-like shape of their leaves lets conifers more easily shed heavy snow buildups.
Part B: Sun Shade Why do some plants have no leaves?
Discuss the need for plants to adapt to environmental conditions. Explore conditions in a desert environment with the students such as hot, dry, wide range of temperatures, high rate of evaporation. Ask the students what type of adaptations they could think that a cactus could have?
Step 1: Cut two sponges of equal size to resemble a cactus.
Step 2: Take one of the dry sponge "cacti." Place toothpicks in it to represent spines. Stand it up with a piece of clay. Shine a flashlight (sun) on the spines. Do you see shadows? How might shadows help to cool the plant?
Step 3: Turn the plant so that the flat, wide part of the pad faces away from the flashlight (sun). Estimate the surface area exposed (thin, narrow edge) to light (sun) versus the surface area not exposed to the sun. How might orientation to sunlight affect a cactus?
Part C: Tree shape.
Ask the students what different shapes they see in different trees. Ask them why they thing trees come is so many different shapes.
Step 1: Unfold the newspaper and lay it on a table.
Step 2: Fold one of the poster board pieces in half by placing the short sides together.
Step 3: Partially unfold the folded poster board, creating a tent shape.
Step 4: Stand the tent-shaped poster board on the newspaper and secure it to the newspaper with tape.
Step 5: Tape one of the short ends of the other piece of poster board to the newspaper.
Step 6: Bend this poster board to form a dome shape, then tape the other short end of this poster board to the newspaper.
Step 7: Using the spoon, sprinkle 4 or more spoons of flour over the top of the tent-shaped structure. Observe how the flour builds up on the structure.
Step 8: Repeat procedure 7, but use the dome-shaped structure.
Results
The tent-shaped structure held little to no flour, while most or all of the flour built up on the dome-shaped structure.
Why?
The tent shape, like the triangular shape of some conifers, doesn't provide a large surface area. Thus like the flour in this experiment, snow tends to slide off the leaves and branches. Though little flour built up on the tent-shaped poster board in the experiment, real triangular-shaped conifer trees have more surface area, so some buildup of snow does occur and some trees do collect more snow than others. At times the weight of the snow will cause tree limbs to break. This opens areas so that sunlight can reach the forest floor and more plants can grow there
Have the students compare the shapes of the trees to the shapes of different roofs.
Part D Effects of Water on a Pine Cone
Step 1: Fill a container with water and place a pine cone in the water for about an hour.
Step 2: Remove the pine cone and observe any changes in the scales. The pine cone closes up to protect the seeds inside the cone. Set the pine cone in a sunny, warm spot for a few hours. As the pine cone dries, it begins to open up again allowing the seeds to disperse.
Step 3: Heat the pine cones in the microwave for a minute on high, be careful that they don’t catch on fire.
Part E Fun with paper Machae
Step 1: Trace and cut out your leaves
Step 2: Rip paper towel into little pieces (I found that the 'quicker picker upper' sucked up too much glue and also the little dimples of the paper towel remained so I would suggest using a less expensive brand...BONUS!!) Mix 2 parts glue and 1 part water
Step 3: Use the twine to make the veins of the leaf
Step 4: Dip the strips of paper in glue/water mixture and glue onto leaf (two layers is sufficient for this project) Do both the top and the underside of the leaf
Step 5: Let it dry for 24 hours or more
Step 6: Paint finished leaf
4. Curriculum Connections
Grade1:
Understandings - Topic E: Needs of Animals & Plants.
1-11 Describe some common living things, and identify needs of those living things.
Grade 6
Understandings - Topic E: Trees & Forests
6-10 Describe characteristics of trees and the interaction of trees with other living things in the local environment
Grade 7
Unit B: Plants for Food & Fibre
Investigate life processes and structures of plants, and interpret related characteristics and needs of plants in a local environment, Analyze plant environments, and identify impacts of specific factors and controls.
1. Ask questions about the relationships between and among observable variables, and plan investigations to address those questions
2. Conduct investigations into the relationships between and among observations, and gather and record qualitative and quantitative data
3. Work collaboratively on problems; and use appropriate language and formats to communicate ideas, procedures and results
4. Attitudes Interest in Science, Mutual Respect, Scientific Inquiry, Collaboration, Stewardship, Safety
5. Investigate life processes and structures of plants, and interpret related characteristics and needs of plants in a local environment
5. Reflections (Effectiveness of Lesson and as a Teacher)