Inside a Flower
Purpose:
To observe and discover the different parts of a flower.
Overview:
Students will work in pairs to name and locate specific structures of a flower through
dissection. They will create a chart that displays all the parts of the flower that they
have just dissected.
Objectives:
As a result of this experiment, children will be able to:
- Identify the reproductive parts of a variety of flowers.
- Observe and compare flower parts.
- Appreciate and demonstrate working in a cooperative group.
Materials:
- Large, easy-to-dissect flowers such as tiger lilies (one per pair). Try to use a variety of large flowers, so the similarities and differences among the flowers are easily observed.
- Hand lenses (one per pair)
- A large piece of plain white butcher paper or large chart paper (one per pair)
- Markers
- Worksheets: "Where am I?" and "Flower Structure" (one of each per pair)
- Plastic knives (one per pair)
- Camera and film (for teacher's use)
- Science journal (one per student)
Motivation:
- Distribute the worksheets to the groups and explain what they need to do. Have them work on them for 10 minutes. They will predict where they think the different parts of the flower are located using the list of hints on the "Where Am I" sheet.
- Discuss each group's findings and show them where each part is really located on the picture. Have them hold onto their worksheets when they are done with the motivational activity. They will need them to identify the parts of the flower that they will be dissecting.
Procedure:
- Distribute the flowers and the rest of the materials to each group. Tell them that they will be dissecting the flower, using the worksheet that they have just completed to locate and name the different parts of the flower. To ensure that all children participating, have them take turns locating a part.
- Tell them that they will be locating the parts that have just been discussed in the sheet on their flower specimen. Explain that the green portion below the flower is the stalk. If you are using a specimen that has a flower cluster, the stalk is called the peduncle. The stalk of an individual flower in a cluster is called the pedicel. When a stalk holds a single flower instead of a cluster, as with the tiger lily and tulip, it is called a peduncle and the pedicel is considered missing. Explain this to the children before they start. Demonstrate all of these with the specimens.
- The children should make sure not to discard any parts of the flower when dissecting them, since they will be drawing each part on their own flower parts chart.
- When the groups reach the pistil (the center of the flower), help the students cut the ovary open so that they can find the ovule. Have the children use the hand lenses to examine the stamen and the ovules. Ask them to find and feel the stigma, and ask why they think it feels that way. (The stigma is sticky so it can catch pollen.)
Conclusion:
When everyone is finished dissecting their flowers, discuss how many stamens each group found. Each kind of flower has a different amount of stamens. Groups can compare/contrast other groups' findings with their own.
Follow-up:
When the groups are done looking around and talking about their findings, have each group start working on their chart. Since the appearance of the flower parts will change over time, they will be drawing each flower part onto a large piece of plain white construction paper. They will also be classifying their plant parts and recording how many they have of each part. (They will discover that the numbers vary according to the kind of flower they are working with.) They can decorate these charts and set them up any way they would like, just as long as they have included each part under the respective headings. These charts will be hung on the bulletin board.
Extension:
Another dissection experiment can be done to compare the differences between incomplete and complete flowers. Flowers that possess all four whorls (sepals, petals, stamen, and pistil) are called complete flowers. Incomplete flowers lack one or more of the four.
Assessment:
The children will write their discoveries in their science journals. They may use drawings to illustrate the parts of the flowers that they have dissected. Have them write about this experience and what they had liked or didn't like about the experiment. As a form of documentation, take pictures of each group as they are working. Also use the charts and the worksheets as evidence of their work.
Background:
Flower Parts
- Peduncle- the stalk of a flower cluster or the stalk of an individual flower.
- Pedicel- the stalk of an individual flower in a cluster.
- Receptacle- the top portion of the peduncle or pedicel that begins to flare out. It supports the remaining flower structures.
Outer Most Whorl - protects the inner parts of the flower and attracts pollinators to the flowers.
- Sepals- part of the outer whorl of the flower; it is a green petal-like structure attached to the receptacle. Individually, they are called sepals; collectively, they're called the calyx.
Second Whorl
- Petals- part of the outer whorl of the flower, individually called petals; collectively called the corolla.
Third Whorl
- Stamen- the two parts of the stamen are the filament and anther. The anther produces the pollen.
Inner Most Whorl
- Pistil- contains the stigma, style, and ovary (where fertilization occurs and where ovules are produced).
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Lessons:
Inside a Flower
Soil Investigation
Flower Investigation
Fruit or Vegetable?
Where Am I?
Seed Dissection
Flowers Galore
Pollination & Fertilization
Flowers & Their Families
Plant Parts & Their Jobs
Identifying Flower Families through Flower Shapes
Brooklyn Botanical Garden Scavenger Hunt
Bibliography
This lesson is part of Flower Power by Rosemarie Young.
Grade Levels:
3-5
Subjects:
Science, Math and Arts
Beginning Grade
Level:
3
Ending Grade Level:
5
e-mail Rosemarie
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