Monday, October 15, 2012

Recipe for a Sunflower - How a Seed Works

In picking the sunflower seeds from the dried flower heads, many students tried cracking them open to see what was inside.  When they saw the kernel inside the harder exterior of the seed, a few remarked that the kernel was the little plant that makes the bigger plant. 

S:  When you cut the seed and pull part of it out, it looks like the egg's hatching. 

Packets of sunflower, bean, pumpkin, and corn seeds were brought in to expand the students' knowledge of how seeds work.  They noted the visual and tactile differences and wanted to investigate how to grow them.

Several children tried to investigate seeds by opening them.

D:             I found a big bean seed.
L:              Inside the pumpkin is a green seed.
T:              Those are the pumpkin seeds, that’s just their cover, their shell.
L:              No seed has a shell.
D:              This one does.
T:              Everyone does.
L:              What about pumpkin seeds?
T:               Yes they do, they need protection.
Why do the seeds need protection?
T:               From birds.
B:               They can still get the seeds in the dirt.
T:               I know they can, but they’re just made like that.

O:     The soil feels good (on my hands).   We’re playing with the dirt.
What is soil?
O:      Soil is dirt that worms move around.
T:       It’s cow manure.
L:       It’s dirt that has nutrients.
T:       What are those little white things? 
N:       Fertilizer.

In talking about the necessary “ingredients” for a “sunflower recipe,” the children offered up their ideas:

E:      Plants soak up the water up.
T:      [With their] roots. They’re kind of like the straw.
D:      It needs nutrients [which are] something that makes it grow.
Do humans need nutrients?
D:      Yes. We get nutrients by being healthy and eating good.
T:       Worms also help plants, to help it breathe.
E:       Rain comes down and it goes into the holes [that the earthworms have created].
T:        It’s actually that when it [the earthworm]comes into it it actually just moves the soil around so that it’s not hard and dry.
K:       I would put it in a sunny place that would probably rain.
Talk about the necessity of soil and water led us to think about testing other mediums to grow the seeds in.  Sunflower seeds were planted in dirt, and then as controls, they tried planting them in rocks and a container of leaves and grass.   
They also talked about how much water the seeds would need and 
how much might be harmful.  
 Is too much water bad?
T:     Yes. It’s like if you were drinking a big glass of water, you couldn’t  drink that water for hours…cause you need to breathe. It’s not like you have gills.
R:     They need air. 

Each student was given their own little “seed baby” sunflower, and they were invited to come out and fill a small glass baby food jar with dirt to help it take root and allowed to give the seeds a sip of water to help them grow.  They were given a choice – to either grow a sunflower seed from a packet purchased at a store or one of the seeds they had picked off the mammoth sunflower.  Of the sixteen children in the class, only four students (F., E., L., and N.) chose to grow a seed from the mammoth sunflower.  Their choices were recorded and, as we monitored the children’s seed growth, we looked to see if one seed proved to grow better and stronger than the other.  
Our Seed Babies
The students were invited to draw the seeds as they grew to note the various changes over time and to note how the controls were working (or not working).

A number of students pursued their interest in expressing the life cycle of the seed.  When a few children drew pictures of the seed growing in stages, they noted that the final stage was when the plant was in full flower.  The question was then asked:  is that the end of the life cycle of the plant? 

L:             Well, even if you cut off the flowers, the plant could still live. 
T:             Its life span would be shorter. 
D:            It has to have a head to live.  It has brains! Just kidding.

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