What on earth's going on? Are you all right?
Well, of course. I'm just helping it grow.
Helping it grow?
Well, I read this article, see, and it said that plants enjoy being sung to.
It makes them grow bigger. So, since I've got a good voice, I thought that I'm...
You know, now you come to mention it, I think I have heard that story somewhere before.
Well, it is a nice story, but there's only one thing wrong.
Oh, what's that?
Well, plants can't hear, or can they?
Ask one.
Oh, look, if they could hear, that would mean that they were alive, like animals.
Well, of course they are. Well, they drink, they move, and they love the sun.
But that doesn't mean that they're alive. Only animals are alive. Aren't they hell?
Life would be very dull if you were right, Bill, but I'm afraid you're wrong.
I'll bet I'm not.
Well, why don't you...
Oh, I know, I know. Ask the professor.
Well, I can understand your confusion.
For a long time, people had thought of living things as belonging to two large groups,
or kingdoms, if you like. That is, the plant kingdom. Oh, yes, they're alive, all right.
And the animal kingdom. And this belief grew because these two kingdoms had ruled
from the very early days of our planet.
At first, only microscopic life existed. Then, from the water, large reptiles began to evolve.
Some were meat eaters or carnivores.
Others, plant eaters or herbivores.
Meanwhile, the first land plants emerged as liverworts and mosses, and later, shrubs and trees.
Now, these groups of living things were accepted right up to the 18th century when a scientist
called Linnaeus found a better way of classifying. For instance, he found that some animals had
For instance, he found that some animals had feathers, some had no backbone, and others did.
And it was the same with plants. Gum leaves are very different to pine needles. He classified them,
too. Oh, aren't they lovely? Anyway, there were other ways of grouping them, too.
Some living things can be grouped by what they eat. After all, even plants like different things.
Some like to live near the sea. A cactus loves the desert. And ferns like cool, damp places, deep in the forest.
And ferns like cool, damp places, deep in the forest.
Oh, that's all very well. But what makes these things live? I mean, they must have
something in common. Ah, they do, Bill. Something that, sadly, I don't have.
That's why I'm only a computer. Oh, well, never mind, Hal. Now, what is it that they have in common?
They're called cells, Kate. Cells? Like prison cells. Oh, not that sort?
No, indeed. Cells are the basic units of life. Yes. In 1665, an English scientist called Hawke
looked through his microscope and saw an amazing thing. He was looking at a piece of cork. And cork,
remember, is a living thing. He saw what appeared to be tiny rooms making up the cork.
So he called them cells, after the Latin word cella, small room.
Scientists then realized that the tree on which the cork grew was itself made up of cells.
And that the tree's growth came as these cells multiplied.
Eventually, they concluded that all living matter grew, as different types of cells
recreated themselves.
I see. And how many cells go to make a living thing? Sometimes just one, Kate. They are the
simplest living things known to us. These tiny single cell creatures are called protists.
They make up the first kingdom. They're the living things no one knew about until recently,
because they were often too small to see. The second kingdom of living things are the plants.
From small plants with millions of cells to large trees with millions and millions of them,
the third kingdom has the most complex cell structure of all, the animal kingdom, with man himself.
And all living things are made up of those little cells. Right. Dividing, multiplying, dying,
and being replaced all the time to build human beings like you. You know, I once made ginger
beer with the yeast and sugar, and the yeast kept growing, dividing and multiplying.
Dividing and multiplying.
Yes, it eats all the sugar, just like a greedy child. And when there's no sugar left,
it stops growing. Food and water are vital to life.
But a carnivorous animal must live with other animals, which it hunts.
But there is one basic thing almost all living creatures need and use.
I know, air. Right, because all living things breathe, even the little single celled protists.
Air, the right food, and water. Yes, I understand that we all need those, even our little friend the
cell. But look, what's some other things that living things have to do? Well, you can see for
yourself, Kate, they move by themselves. I mean, a rock can't move because it's not alive,
but animals and plants, big and small, move in all different ways.
And there is another thing you living beings do.
We, uh, talk. An amoeba talk? He hasn't got a tongue. No, no, you all sense. Sense? What's that?
A sense is what tells the body about changes in the environment.
Living things have many senses. Seeing, hearing, tasting, smelling,
and touching. All your knowledge is based on your senses.
In some animals and plants, some senses are stronger than others.
All right. Well, we move and we breathe and we sense and then we eat and drink to give us energy.
But what's all this about the sun? Now, the sun seems to be the key to it all once again.
Well, I suppose it's because the sun acts upon living things to sustain life. Well,
take a tree and its leaves, for example. Now, the sun's energy helps the tree to change water
and air and minerals into food for the tree and for other living things.
Well, I don't know. It's all a bit complicated. Look, if all living things are breathing and eating
and moving about, well, very soon it's a wonder there's no water or air left. That's the whole
point, Bill. All you living things depend on each other, particularly human beings. You all need
each other. For instance, where would you be without fruit or vegetables or meat and fish?
Oh, hungry. Exactly. The world is very delicately balanced, Bill. Plants and animals depend on each
other for survival. They're all part of the food chain that begins with the sun.
Hal, I know that plants are useful to animals and humans in the food chain, but
well, how else do we benefit? Well, the main gases in air are oxygen and carbon dioxide.
You animals breathe in oxygen and use it up as fuel. You breathe out the carbon dioxide
because you don't need it. All plants and animals do that, but plants do the opposite
when they're exposed to light. Oh, I see. So that when the plants are in the light,
they're giving out oxygen and that makes more oxygen for us to breathe.
No wonder I feel better in the country. The air really is better. Sometimes I feel I'm missing out
on something. You humans do have a lot of friends, you know. Oh, we're your friends, Hal.
Why, you help us the way that we help the plants and they help us. However, it's not all joy in
the garden, Kate, because in order to survive, plants and animals have to live with and off
other plants and animals. Scientists call the process succession.
Succession had evolved amongst the plants and animals
millions of years before man appeared. After all, dinosaurs had to eat an awful lot.
Like other animals, adapted to his rather nasty environment by growing
a spiky protection. It made him less of a mouthful.
Still other animals developed their own protection.
But the dinosaurs failed to adapt enough. Gradually, they vanished from the
earth. And to succeed them, the mammals have continued to adapt to their environment
right up to the present. Of course, today, all kinds of living things have adapted
to their environments. For instance, this tree has bark for protection.
While most flying creatures have wings and fish can breathe under the water.
Well, it's to his own. I'm certainly glad that I haven't grown bark or
gills. You would look interesting. Hey, but don't forget that human beings have adapted to,
you know, over many millions of years. Why, some people can even communicate with other living
things. Can't they, Bill? True, true. Maybe I'll sing him another song.
Bill, what if it's a female plant? Oh, well, uh, I...
That is an entirely different question. But I can tell you about that.
Oh, Hal, I think we'll save that for another program. One thing about you, Hal.
Well, you can't talk back now. Bye.
Bye. Till next time.
Bye.