Science 4: Plant Structures
How do plants work? We tried asking the willow tree in our back yard, but it's giving us the silent treatment.
|Elementary and Middle School||4th Grade|
Oh, but before we sign up, maybe we should dig a little deeper into the secret life of [Plant is dug up]
As it turns out there's a lot going on that we can't see.
If we take a look under the hood there are all sorts of intricate structures that keep
plants growing and living.
Let's start at the bottom with the roots.
One of their main jobs is to pull water and minerals from the ground, then deliver it [Water and minerals travel up the roots]
to the stems and leaves of the plant.
They also give support to the plant by anchoring it to the ground, meaning it won't just fall [Anchor appears]
over or blow away due to the slightest breeze. [Plant leans over in the wind]
Which is both good for the plant, and good for anyone who would rather not be hit in
the face by hundreds of plants on a windy day. [Man is hit by plants and falls over]
Next comes the stem.
It keeps the plant upright once it shoots above ground...
…and it's also in charge of transporting water, minerals, and sugar through the plant,
like a miniature highway system. [Water, minerals and sugar travelling through the plant]
And luckily, the commute from the roots to the leaves is pretty short, so there's never [Traffic jam on the highway]
any fear of getting stuck in a huge traffic jam!
The stem itself is made up of two internal structures that move all the water, minerals,
and sugar around…they go by xylem and phloem. [Arrows point to the different transportation systems]
The xylem moves the water and minerals up from the roots all the way up to the leaves…
…while the phloem moves sugars downward.
And you might be wondering: where did those sugars come from?
Well, as cute as it would be, there isn't some kindly old granny that hands out sugar [Woman dropping sugar cubes into a plant]
cubes to plants.
The plants actually make the sugars all by themselves, with their leaves.
Through photosynthesis, a process that also helps the plant to get rid of oxygen and take [The sun appears]
in carbon dioxide.
We're not sure we want to be a plant anymore…we kinda like oxygen… [Womans head on a plant can't breathe]
Another important part of plants is the flower.
Its function is to attract pollinators, which are important in plant reproduction. [Bee lands on a sunflower]
Unfortunately, flowers do also on occasion attract shear-wielding gardeners. [Man appears with shears]
It's not quite a perfect system.
And last but not least, plants also rely on fruits and seeds. [An apple tree]
The seed itself produces offspring…
…while the fruit protects the seeds. [Apple holding a sword]
So next time your parents go to the grocery store, be sure to ask them to pick up some
fresh "Plant Offspring Protectors."
Mmm…sounds delicious. [Parents look confused]