Discovering
FLOWERS
in a
New Light
By Rebecca L. McNall
and Randy L. Bell
TRACEY SHIPLEY
Students explore flowers up close
with a digital microscope and use
their observations to predict the
functions of flower structures.
C
hildren love observing seeds change as
they germinate and grow into tall healthy
plants, but how do you make investigating
plants an exciting and immediate event? Microscopy might just be the answer. Although most
students have seen flowers, not many have looked
closely at their various structures or seen their
colorful designs only apparent when magnified.
January 2004 35
anther
In our elementary science methods course, we used
digital microscopes for such a study and were pleased
with the results. We developed this language-arts-and
technology-integrated inquiry lesson to model how to
effectively incorporate technology into a fourth-grade
science lesson on flowers. The activities followed the 5E
learning model (Engage, Explore, Explain, Elaborate,
and Evaluate) developed by the Biological Sciences
Curriculum Study (BSCS 1989) and addressed National Science Education Standards.
Going Digital
TRACEY SHIPLEY
In digital microscopy, the
computer screen becomes
the microscope eyepiece,
making focusing specimens
easier and providing
opportunities to view the
images as a class.
36
Science and Children
The National Science Education Standards for grades
K–4 recommend elementary students begin using microscopes to observe the finer details of plants early in
their science experiences (NRC 1996). In digital microscopy, the computer screen becomes the microscope eyepiece, making focusing specimens easier and
providing opportunities to view the images as a class.
Another advantage of digital microscopes is the ability to take snapshots and save these images. In most
cases, this can be done by simply clicking a button.
These images can also provide useful assessment applications, as they can be exported into a word-processing
document and labeled.
There are several affordable digital microscopes
available today that are designed for use in elementary
classrooms, such as the DigiScope (available from
Ward’s Natural Science, Science Kit and Boreal Laboratories, and Edmund Scientific) and the Digital Blue
QX3 (see Internet Resources).
Before beginning the flower lesson, we completed a
short activity investigating how many “Lincolns” students could find on a penny. This allowed students to
practice using the digital microscope and to learn to use
the snapshot feature.
Engaging with Literature
The first phase of the 5E learning cycle model—engage—is designed to interest students in the topic,
generate curiosity, or uncover what children already
know about the topic. To begin the lesson, we read The
ovules
Magic School Bus Plants Seeds (Cole 1995), but there
are many other titles that would also be appropriate,
such as The Tiny Seed (Carle 1991) or The Reason for a
Flower: World of Nature (Heller 1983).
We introduced the story by asking our students to
describe their experiences growing seeds. A few recounted their experiences growing a garden or planting
window boxes at home. For fourth-grade students, this
discussion would help make connections and establish
a relevant context for learning about flowers.
Before reading the book, we discussed what details
teachers could ask students to observe, such as the
colors of flowers in the pictures or the insects that appear
in the book. After reading the story, we briefly reviewed
what students noticed—the bees that were attracted to
the flowers, the wind dispersing the seeds, and the nectar
in the flowers.
Exploring Flowers
It was time to move on to the second phase of the
learning model—exploration. During this phase, students investigate a topic—in this case, flowers—
through hands-on experiences that help them formulate and test hypotheses; record observations; discuss
ideas with other students; and gain experiences with the
scientific phenomenon or concept.
To begin, we asked students if they had ever taken a
close look at flowers and noticed their different shapes
and structures. We then asked students to sketch a
flower from memory, including as much detail as they
could remember. This assessed students’ current
knowledge and generated curiosity as they prepared to
examine real flowers.
In our lesson, students examined Alstroemeria flowers. (These are commonly found in grocery store floral
departments for around $5 a bunch.)
For elementary students, it is best to use large flowers
with easily identifiable parts. Other examples include
lilies, daffodils, and irises. Composite flowers, such as
daisies or sunflowers, are not good for young children to
work with because the components of their numerous
small flowers are not easily identified.
stigma
pollen
Another advantage of using digital microscopes is the ability to save snapshots for later use. These close-up shots of
Alstroemeria flower structures were used for class presentations and worksheets.
For these activities, students worked in groups of
four to foster interpretive discussions during the activities. To begin the activity, one flower was distributed to
every student in each group. We reviewed safety rules,
such as never tasting any part of a plant and always
washing hands thoroughly after handling plants. Other
safety precautions can be found in the NSTA book
Safety in the Elementary Science Classroom (NSTA
2003). (See the NSTA Connection at the end of this
article for a link to information about this book.)
We asked students to draw a diagram of the
Alstroemeria flower next to their initial sketch, asking
questions to help focus their observations, such as Do
you notice any structures inside the flower? What do they
look like? Are they all the same?
After students had an opportunity to study their
flowers, the teacher demonstrated the removal of the
petals to expose the reproductive structures and explained how botanists pay close attention to the intricate characteristics of flowers. Students were encouraged to use hand lenses to identify the flower’s markings, textures, and structures and to record their observations in their notebooks.
Up Close and Amazing
Once students had observed the parts of the flower
with eyes and hand lenses, they were ready to use
the microscope to improve upon those observations. We asked students to carefully place one of
the “stalks with a brown, round top” from the flower
under the microscope.
Although the flower images seen at l0× magnification looked similar to what the students had observed
using hand lenses, higher magnifications (200×) exposed new structures and features they had not noticed
earlier. Students were amazed to discover the brown tip
of the stalk was actually covered with “ricelike” pieces!
January 2004 37
PHOTOGRAPHS COURTESY OF THE AUTHORS
pistil
Although these students were familiar with pollen,
most students recalled from past experiences that pollen looked like yellow powder, not small, off-white rice
grains. After observing pollen grains for a few minutes,
we demonstrated how to remove the remaining browntipped structures (stamens) to reveal the innermost
stalk (pistil). We then asked students to observe the
details of the tip of this structure at 60× and 200×.
During this phase, we moved from group to group,
helping students focus microscopes and take snapshots, which they saved for later use. We asked students
to predict what purpose various structures served for
the flower, using their observations to guide their ideas.
For example, many students identified the tip of the
central part of the flower (stigma) as the structure that
“captures pollen” because of the hairlike structures with
glistening tips they observed.
Part of the fun and excitement of this activity was the
next step—dissecting the base of the flower (ovary). We
demonstrated how to split open the base of the flower
vertically. Because Alstroemeria flowers are soft, they were
easy to split open using only fingernails. (Toothpicks
could be provided if students need additional tools.)
Viewing one-half of the flower’s ovary under the
microscope elicited lots of “oohs” and “ahhs!” The
teacher challenged students to hypothesize the purpose
of the small oval structures (ovules) they observed
inside the base of the flower. They proved the most
challenging structure to identify. Initially, students
were baffled at what these structures could be. “Are
they seeds?” one student wondered. Another suggested, “Maybe that is pollen.” After discussing possibilities with other members of their group, some correctly suggested they might be potential seeds.
Form and Function
Students continued their explorations until they
showed interest in knowing the names of the structures,
moving the class into the third phase of our 5E learning
model—formulating explanations from students’ experiences. Probing questions guided students’ discussion, such as What is that part?, What do you think the
function of that structure is?, and What have you observed that makes you think that?
This was an appropriate time to introduce proper
names of the structures students had observed—stamen, pistil, stigma, pollen grains, ovary, and ovules—in
the context of students’ experiences.
The students used a labeled diagram of the flower
to help them identify the names for each structure.
You could also provide additional resource materials,
such as Eyewitness Visual Dictionaries: The Visual
Dictionary of Plants (Bown 1992), or posters illustrating the parts of the flower.
38
Science and Children
Using student snapshots projected on a screen, we
discussed what students had observed under the microscope, noting surprising features and sharing the
names and functions they identified for each structure. This challenged students to use their observations to match the form and function of the flower
structures. For example, students easily identified the
anther of the flower as the part that produces pollen
because they had observed a mass of pollen grains on
these brown structures.
After the Alstroemeria investigation, the students inserted the flower images they had saved from the digital
microscope into a word-processing document—an electronic worksheet—and then labeled the names of the
structures and their functions (see NSTA Connection).
One Step Further
Now that students were familiar with the basic parts of
one type of flower, we wanted them to apply this knowledge to other flowers in the fourth stage of the 5E
learning cycle—elaboration.
In this part of the investigation, we provided each
group of four students a different flower (lilies, carnations, and other readily available flowers) than the one
they had initially investigated. We asked students if
they believed they would find similar parts in the other
flowers. Though hesitant, they believed so.
Students compared their Alstroemeria sketches to the
structures they observed in the new flowers. Because of
their previous experiences, students were able to identify pistils and stamens, noting similarities and differences. For example, several students noted the similarity in location of the pistil. One student noted that the
tip of the carnation’s pistil was much longer and curled
compared to that of the Alstroemeria. Another student
commented on how the petals of the carnation concealed the anthers.
They again used the digital microscope to take snapshots and labeled each part from the new flowers so
they could share their findings in a class discussion.
This exploration allowed students to expand upon
concepts introduced in the first lesson. They noted
that all of the flowers they observed had similar structures, including the stamen, pistil, and ovary. They
also found ovules in each of the flowers they observed. This activity also helped awaken their curiosity about flowers and apply their understandings to
the world around them.
Knowledge Is Blooming
Although evaluation is the last phase in the 5E learning
model, it should be a continuous component as the
lesson progresses and the teacher assesses students’
changing understandings of the concepts.
A final assessment task helped students assimilate
the new information gained in this investigation. As
a culminating project, each group presented their
flower to the class. Using their snapshots, they identified the major parts of their specimen and explained the characterisitics that helped them identify
the structures.
Students could also print out the images of flower
structures and display these on a bulletin board to
illustrate the similarities in the pistils, stamens, and
ovules of the different flowers.
Summing Up
This lesson illustrates how technology can engage students in scientific inquiry. As technology becomes
ubiquitous in schools, teachers must find ways to incorporate these tools in ways that provide experiences
beyond what students could learn through other, “lowtech” approaches. In this activity, the digital microscope provided a close up view of flower structures and
a means to save observations as snapshot images that
were later used to scaffold class discussions. There are
many ways to incorporate technology tools in science
instruction. However, it is important for teachers to be
critical users of technology as they explore innovative
ways to engage children in learning science and foster
scientific inquiry. n
Rebecca L. McNall ([email protected]) is an
assistant professor of curriculum and instruction at
the University of Kentucky in Lexington, Kentucky.
Randy L. Bell is an assistant professor of science education at the University of Virginia in
Charlottesville, Virginia.
Resources
Biological Sciences Curriculum Study (BSCS). 1989. New
designs for elementary school science and health: A cooperative project of Biological Science Curriculum Study(BSCS)
and International Business Machines (IBM). Dubuque,
Iowa: Kendall/Hunt.
Bown, D. 1992. Eyewitness Visual Dictionaries: The Visual
Dictionary of Plants. New York: Dorling Kindersley.
Carle, E. 1991. The Tiny Seed. New York: Simon and Schuster.
Cole, J. 1995. The Magic School Bus Plants Seeds: A Book
About How Living Things Grow. New York: Scholastic.
Heller, R. 1983. The Reason for a Flower: World of Nature.
New York: Grosset and Dunlap.
National Research Council (NRC). 1996. National Science
Education Standards. Washington, D.C.: National
Academy Press.
National Science Teachers Association (NSTA). 2003.
Safety in the Elementary Science Classroom. Arlington,
Va.: Author.
Connecting to the Standards
This article relates to the following National Science
Education Standards (NRC 1996):
Content Standards
Grades K–4
Standard A: Science as Inquiry
• Abilities necessary to do scientific inquiry
Standard C: Life Science
• The characteristics of organisms
Digital Microscope Resources
Science Kit and Boreal Laboratories
sciencekit.com
Ward’s Natural Science
wardsci.com/
Digital Blue
playdigitalblue.com/home/
Edmund Scientific
scientificsonline.com/
Internet
Exploring the World of Optics and Microscopy
micro.magnet.fsu.edu
This is a comprehensive website providing background information on various optics topics, including digital microscopy and photography. The website includes an online tutorial for the QX3 digital microscope and the Olympus MIC-D
digital microscope with many examples of images and video
clips taken with both microscopes.
University of Illinois Extension Schools
www.urbanext.uiuc.edu/SchoolsOnline/index.html
University of Illinois Extension has designed several interactive reading modules (including suggested hands-on activities) for students in grades three through five on science
topics such as plants, gardening, weather, and animals.
Kidsgardening.com
www.kidsgardening.com/teachers.asp
This website, developed by the National Gardening Association, is geared toward elementary children and provides ideas
for designing a garden and other hands-on activities.
NSTA Connection
There are several additional items related to this article available online. Click on this article at www.
nsta.org/elementaryschool to view
• NSTA guidelines for using plants in the classroom;
• An electronic worksheet created during this lesson;
• Additional flower resources; and
• Downloadable flower images.
January 2004 39