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Sustainability Lesson Clearinghouse
Dissecting a Flower
Lesson Description:
In this activity students take a closer look at the flowers they see every day in local gardens or in their schoolyard. By dissecting a flower, they can easily examine its parts to gain a greater understanding of the process of pollination. Students can record observations in a nature journal and compare their flowers to those of their classmates.
Eco-fact: Wolffia blooms are the smallest flowers in the world, growing to only .2 to .5 millimeters wide and .9 millimeters long. In fact, a dozen wolffia flowers could easily fit on the head of a pin.
Procedures:
Prior to dissecting a flower activity:
Teachers and their students can gather flowers from around their own garden, depending on the number of blooms that they have available. Remind students not to take too many flowers from the same plant. Another option is to buy flowers from your local market for the purpose of the activity. Remember to find flowers that have both male and female parts such as lily, daffodil, tulip, apple, garlic, onion, pepper or tomato flowers.
Background information about pollinators:
Pollinators include thousands of species of insects, including bees, wasps, flies and butterflies as well as other animals, like bats and birds, especially hummingbirds. Pollinators are creatures that help plants reproduce by moving pollen from one flower’s male anther to the female stigma of another. Once pollination has taken place, seeds begin to develop. Pollination can also occur with the help of wind, or occasionally water. Some plants even pollinate themselves.
The shape, color and fragrance of flowers all serve to attract certain species of pollinators. For instance, flat-topped flowers such as zinnias act as resting spots for butterflies, and the strong fragrance of lilies attract a number of insects, including bees.
Dissecting a flower activity:
1. Flower examinations can begin by looking at the top of the stem, just below the flower petals. Have each student locate what looks like small green petals. It isn’t actually petals, but a part of the flower called the sepal. Most flowers have them, but some, like amaryllis, don’t have any at all.
2. Tell the class to look at the petals. Ask the class what they think is the purpose of the petals. Their beautiful color, shape and arrangement are meant to attract pollinators like bees and butterflies. However, they also play an important role of protecting the other parts inside.
3. Have the class carefully peel off the petals to get a closer look at the parts inside the flower. Look for the male parts of the flower, known as the stamen. They look like long delicate stalks with a small, oval ball on the end. Stamens are broken up into two parts, the long strands called the filaments and the small, pollen carrying, oval balls called anthers.
4. Students can carefully touch the anther to expose some of the pollen. Usually pollen is a yellow or orange powder like substance, but sometimes it can be other colors as well. If no pollen comes off, that means that the flower isn’t ready for pollination yet.
5. Next the students can remove the stamens to reveal the thicker, central strand called the pistil, the female part. The end of the pistil, called the stigma, is often very sticky. During pollination the stigma catches the pollen to bring it down the tube to the ovary. The ovary is where seeds form at the thick area at the bottom on the flower.
6. Students can break open the ovary to uncover the ovules inside. The ovule is the female reproductive cell that will develop into a seed when fertilized by pollen.
After dissecting a flower activity:
Adaptations:
In this activity students take a closer look at the flowers they see every day in local gardens or in their schoolyard. By dissecting a flower, they can easily examine its parts to gain a greater understanding of the process of pollination. Students can record observations in a nature journal and compare their flowers to those of their classmates.
Eco-fact: Wolffia blooms are the smallest flowers in the world, growing to only .2 to .5 millimeters wide and .9 millimeters long. In fact, a dozen wolffia flowers could easily fit on the head of a pin.
Procedures:
Prior to dissecting a flower activity:
Teachers and their students can gather flowers from around their own garden, depending on the number of blooms that they have available. Remind students not to take too many flowers from the same plant. Another option is to buy flowers from your local market for the purpose of the activity. Remember to find flowers that have both male and female parts such as lily, daffodil, tulip, apple, garlic, onion, pepper or tomato flowers.
Background information about pollinators:
Pollinators include thousands of species of insects, including bees, wasps, flies and butterflies as well as other animals, like bats and birds, especially hummingbirds. Pollinators are creatures that help plants reproduce by moving pollen from one flower’s male anther to the female stigma of another. Once pollination has taken place, seeds begin to develop. Pollination can also occur with the help of wind, or occasionally water. Some plants even pollinate themselves.
The shape, color and fragrance of flowers all serve to attract certain species of pollinators. For instance, flat-topped flowers such as zinnias act as resting spots for butterflies, and the strong fragrance of lilies attract a number of insects, including bees.
Dissecting a flower activity:
- After gathering flowers and returning to the classroom, students will dissect their flowers step-by-step. After each step students will record observations and create drawings/diagrams in their nature journals.
- Write the name of each flower part on the board for student use in recording observations and drawing diagrams.
1. Flower examinations can begin by looking at the top of the stem, just below the flower petals. Have each student locate what looks like small green petals. It isn’t actually petals, but a part of the flower called the sepal. Most flowers have them, but some, like amaryllis, don’t have any at all.
2. Tell the class to look at the petals. Ask the class what they think is the purpose of the petals. Their beautiful color, shape and arrangement are meant to attract pollinators like bees and butterflies. However, they also play an important role of protecting the other parts inside.
3. Have the class carefully peel off the petals to get a closer look at the parts inside the flower. Look for the male parts of the flower, known as the stamen. They look like long delicate stalks with a small, oval ball on the end. Stamens are broken up into two parts, the long strands called the filaments and the small, pollen carrying, oval balls called anthers.
4. Students can carefully touch the anther to expose some of the pollen. Usually pollen is a yellow or orange powder like substance, but sometimes it can be other colors as well. If no pollen comes off, that means that the flower isn’t ready for pollination yet.
5. Next the students can remove the stamens to reveal the thicker, central strand called the pistil, the female part. The end of the pistil, called the stigma, is often very sticky. During pollination the stigma catches the pollen to bring it down the tube to the ovary. The ovary is where seeds form at the thick area at the bottom on the flower.
6. Students can break open the ovary to uncover the ovules inside. The ovule is the female reproductive cell that will develop into a seed when fertilized by pollen.
After dissecting a flower activity:
- After students have finished dissecting their flowers, they can make a model of a flower by arranging and reconstructing all the flower pieces and gluing them onto a piece of construction paper or cardstock. Then they can label all the flower parts.
- Conduct a discussion about the parts of the flower that students discovered as they they examined their flowers.
Adaptations:
- This dissection activity could be conducted outdoors.
- The same experiment can be performed on other flowers. Students can compare the similarities and contrast differences from the previous flowers they examined.
- The discussion answers to prompt questions can be recorded in their nature journal.
Lesson Type:
- Discussion
- Experiment
Sustainability Topic:
- Ecosystems
- Gardening
GEF Program Category:
- Green Thumb Challenge
Time Needed:
30 - 50 minutes
30 - 50 minutes
Materials Needed:
- Card stock or construction paper
- Glue
- Pencil
- Flowers that have both male and female parts such as lily, daffodil, tulip, or a flower from apple garlic, onion, pepper or tomato plants. (flowers such as squash and melon do not.)
- Nature journals
Submitted By:
Green Education Foundation
Green Education Foundation
School or Group:
GEF
GEF
Contact Email:
service@greeneducationfoundation.org
service@greeneducationfoundation.org
Located in: Science