Hi. It's Mr. Andersen. And I'm going to show you how to find the stomata in a leaf and
look at them underneath a microscope. And so basically I'll be using two types of leaves
today. I'm going to use a dandelion leaf which is a dicot. You can see that its veins are
branching out. And then I'm going to use a monocot leaf. And this is a simple blade of
grass that I just picked outside. And where the stomata are going to be found is a little
bit different in a monocot and a dicot. But if you look at them, to the naked eye, and
most trees will put a lot of their stomata on the underside. If you look at a leaf with
just a naked eye, you can't see it. And really you can't see a stomata in general. Because
a stomata is simply going to be an opening or a hole in the leaf. It's going to be surrounded
by guard cells. And the guard cells can open and close to regulate the amount of water
that goes out and carbon dioxide that comes in. But basically this is all you need. Two
leaves. You're going to need a little bit of finger nail polish. I use, make sure you
use clear finger nail polish. I'm using Sally Hansen's hard as nails. You're also going
to need a little bit of transparent tape. And then finally you're going to need a microscope
slide. Now you can do this, but you're never going to be able to see the stomata unless
you actually have a microscope. And so what's the first thing you do? You're going to take
your leaf and you're going to paint a small section on the underside of it with some of
this fingernail polish. It doesn't have to be super thick. The more thick it is the longer
it's going to take for it to dry. And I'm going to paint another little section on the
underside of the dandelion leaf. Like that. And now you simply want to let it dry. And
so basically I'll let you see this. So I've painted on the underside of the leaf. And
now I want to let it completely dry so that basically what I'm doing is I'm getting that
fingernail polish to adhere to the epidermis or the top layer on the leaf and then I'll
be able to pull it off. So this takes a little while. And so I'm just going to sit back and
read. And maybe speed up the video a little bit. Okay. It looks like the leaves are dry
now. And so a good way to tell that is if you just touch on it. If it's not tacky anymore
than it should be good to go. So both of these are ready. Basically what I'm going to do
is I'm going to take a little bit of tape. I'm then going to put it on the section where
I've painted. And then you're going to push down. You have to push down a little bit.
So you're going to apply a little bit of pressure on it. You want to make sure that you've covered
every place of the leaf. And then essentially what you're going to do is you're going to
peel it off. And if you do it really carefully what you'll get is an impression of the leaf.
Now I can just simply put that on my microscope slide. So it can look like that. And so basically,
I don't know if you can see that, but what we know have is an impression of just the
epidermal cells. We pulled all of the epidermal cells off the top. And hopefully we've pulled
off the stomata. So let me do that again with the grass. So with the monocot. Same thing.
Going to push down on it. Like that. You've got to apply a little bit of pressure with
your thumb. And I'm just going to pull it off. So I'm going to get the same thing here.
Okay. Now I don't need these leaves anymore. I'm going to get my microscope and I'm going
to take a look at this. Alright. So I can see the cells, the epidermal cells. And now
as I zoom in even closer I can start to see individual stomata. And so they're going to
be spaced kind of randomly in a dicot. And then if I move over to the monocot, let me
find that. And so in a monocot since all of the veins go in the same direction the stomata
are just lined up perfectly along that. And so again, what am I looking at? I'm looking
and the guard cells. The guard cells are going to be those cells that surround the stomata.
They regulate what gets in, what gets out. And I hope that's helpful.