Lesson
1: Journey
to the Center of a Seed
 The following activity is from the curriculum guide GrowLab:
Activities for Growing Minds. This curriculum brings plant-based
explorations to life through 46 lesson plans and hundreds of
extension activity ideas that spark students' curiosity about
plants and invite them to think and act like scientists. Developed
by NGA and written and field-tested by educators, this complete
curriculum uses fun, illustrated activities to explore plant
life cycles, examine plant diversity, and investigate the interdependence
of plants, humans, and other living and non-living things.
Click
here for more information or to order this guide.
Overview
Students observe, sort, and classify a variety of seeds according
to different properties, and then take a journey inside a bean
seed to predict and observe changes that occur during seed germination.
Standards
addressed: click here
Time:
Groundwork: 30 to 45 minutes
Exploration: 5 to 8 days, 10 to 15 minutes per day
Making Connections: ongoing
Materials (per group):
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dried
lima beans (one per student)
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Advanced Preparation:
Prior to the activity, obtain a mixture of seeds of different
colors, textures, and sizes. Large seeds like beans, corn,
peas and squash are easiest for young students to handle. Try
to locate some fuzzy or fluffy seeds (tomato, dandelion, milkweed).
Old seeds from outdated seed packets are ideal for Groundwork
activities. Old film canisters or small envelopes can be used
to store seed mixtures for individual groups.
Laying the Groundwork
Objective:
To sort and classify seeds by external characteristics.
1. Give each pair or small group of students ten to fifteen
assorted seeds. Ask each group to discuss how their seeds
are alike and how they’re different, and then sort seeds
into groups according to the way they look. Give some examples
for grouping such as: rough and smooth, dark colored and
light colored; large and small.
As a class, discuss the different properties that the students
used to sort the seeds. Put up a class chart with the headings:
size, shape, color and texture (and any other properties such
as smell, that might have been suggested). Ask the class under
which category each of their descriptive words belong. For example:
Size |
Shape |
Color |
Texture |
huge |
oval |
brownish |
rough |
tiny |
round |
tan |
fuzzy |
big |
bumpy |
spotted |
smooth |
long |
|
red |
bumpy |
2. Continue
focusing on seed observations by conducting one or all of the
following activities:
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Invite
small groups to play “I’m thinking of…” with their pile of
seeds. One student thinks of and describes a particular seed
to the other students, who must carefully observe and guess
which
seed is being described. Or, have the audience ask “yes” or
“no” questions about the description of each seed.
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Play a seed Memory game. Have pairs of students carefully observe
a mixture of seeds. Then have one student remove and hide just
one of the seeds from the group. The other must describe the
missing seed.
3. When the above activities are complete ask: How
do you think these seeds with different outsides look inside?
What do you
think you might find inside a seed? What have you ever observed
to make you say that? Give students each a lima bean seed. Ask
them to draw a picture of what they predict it looks like inside.
Exploration
Objective: To discover what’s inside a seed, to predict how seeds
will change after sprouting, and to observe the sprouting (germination)
process.
1. Give each pair of students two lima bean seeds (from step
3 above), ½ cup
of water, and a hand lens. Have them place their seeds in water
for twenty-four hours
and examine them regularly.
Be sure to start some extra seeds, in case some don’t germinate.
Ask: What do you predict will happen to the seeds while they
are soaking?
2. After twenty-four hours, ask: How
did your seeds change while they soaked in water? Did this
match your prediction? What do
you think was happening inside the seed? Have students in each
pair help one another carefully peel the outer coat from one
of the seeds. Then guide them or help them to pull the coatless
seed in half with a fingernail.
3. On the same drawing students made in
step 3 above, ask students to draw
a picture of the inside of one of the split seeds. Ask: How
does what you see inside the seed compare to your original
prediction?
Does any part of the inside
of the seed look like a familiar plant part? Which? Do you
think the seed is alive? Why or why not?
4. Have students place their seeds (both the whole bean seed
and the seed that was split in half) in a plastic bag with a
moist paper towel for a week. Ask: What do you predict will happen
to the seeds during the week?
5. Continue observing the seeds daily for a week. Students should
record changes by making new drawings next to their originals.
Consider having students make a growth chart to record changes
during germination, by folding a long strip of paper like an
accordion and clipping it with a paper clip. Draw on one section
at a time as the seed grows. When complete, unfold to view the
sequence.
6. At the end of the week, discuss findings. Ask: How did different
parts of the seeds change during the week? What happened first?
Next? Did everyone’s seeds change at the same speed? In the same
order?
Just
budding in: If you germinate one bean seed every day for
seven day, you’ll end up with all the stages of germination
at one glance!
Making
Connections
Possible discussion questions:
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Which
different parts of the seed turned into what you predicted?
Did any surprise
you? Which?
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Do
you think seeds are living or non-living? What did you observe
to make you believe that?
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After
exploring seeds inside and out, why do you think seed coats
are so hard?
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What
new questions do you have about your seeds?
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Plant
your seeds and continue to observe and measure growth using
a variety of measurement methods.
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Have
students secretly line up assorted seeds in certain sequences
(smallest to largest)
or patterns (rough-smooth-rough).
Challenge
other students to guess the sequence
or pattern.
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Investigate
the power of growing seed. Fill a plastic container (e.g. yogurt)
with pea or bean seeds and add
water.
Seal the
container and watch what happens
once the seeds have expanded overnight.
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Find
about monocots (e.g., corn and other grasses) and dicots (e.g.,
bean,
pea, tomato). Compare the
insides
of these seeds
and observe differences in
early growth.
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Design
and construct a chamber, using recycled materials,
to view
seed growth.
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Generate
a list of seeds eaten by humans.
Consider
those that
are eaten whole
(rice, peanuts) and those
that are processed
so they don’t
resemble seeds (wheat
flour).
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Make
a list of questions
you would
ask a young
plant as
it grows from a
seed.
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Act
out the process of seeds
growing.
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Create
seed dolls
by rolling
up seeds
such as
grass seed
in moist
paper towels.
Cut out
holes for
arms and
legs. Seeds
will sprout
from these
holes and
from the
top.
Copyright© 2006 National Gardening Association
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