Fun Science: Plants
Professor Gizmo (Amazing Science Presentations) gives expert video advice on: Are there plants that eat bugs?; How old is the world's oldest tree and how do we know?; Why does fruit ripen? and more...
How do plants help us breathe?
Actually plants don't help us breathe in the actual breathing process, but plants will take in carbon dioxide, and they'll produce oxygen. Well our bodies, when we're breathing, we take in oxygen and we produce carbon dioxide, so plants and animals are a perfect fit, because we give off the carbon dioxide, and plants need the carbon dioxide, and they give off the oxygen, and we need to oxygen. So plants are necessary for us to breath.
What is "photosynthesis"?
Photosynthesis is the process where plants actually make food. They will take in the carbon dioxide that we try to get rid of. They'll take in water and they need energy, and the energy comes from the sun. So actually they need water. They need sunlight and they need carbon dioxide and they turn that into food, which is sugar and in the process of making that, during photosynthesis, the plants give off oxygen which we need.
Why do some leaves change color in the fall?
Leaves will change color in the fall because they have a lot of pigments in them. Most plants are green, but in the fall, the mechanism for feeding the plant is cut off. And when this happens, the chlorophyll disappears, and then the other pigments that are underneath the chlorophyll begin to show through, so you'll see your reds, yellows, browns, and then the green fades away. The leaves don't then get green again, because when they turn brown, the leaves will drop off. Then in the spring, the new leaves will grow back, and since they're growing back and they're being nourished by the roots of the plant, they'll start producing more chlorophyll which they need to make food, to keep the plants alive.
How do seeds grow into plants?
Inside every little seed there is a tiny plant. Before a plant produces a seed or releases the seed, it provides a storage place for food for that plant to grow. When that seed falls off, it has stored food and has a little seed in it with a protective coat, so that if conditions aren't right, they won't grow. But the protective coat will keep the seed viable. Then, when the seed gets into an area where it can grow, the nourishment is released from the stored food. Because of the moisture that's getting in there, the little plant that's in there starts growing and turns into a new plant.
How do plants drink water?
Plants will drink water through capillary action. If you take two pieces of glass and stand them up next to each other and then set them down into water...once you put them together, the water will just rise up in between them. That's basically how capillary action works. Some plants have water conducting tissue called zylum in the middle of the plant that carries water up. There are also tubes in the plant that are called floam, which carry food around the plant.
Are there plants that eat bugs?
There are some plants that are carniverous. Some plants have a very putrid smell, and they'll attract insects. Some of them trap the insects by having them get stuck in a fluid. Some of them actually close like the Venus Flytrap; it has hairs in there which trigger the plant, and causes it to close over the fly or mosquito or whatever bug happens to get in there. They use that protein to survive. A lot of those plants live in an area such a bog where there isn't much in the way of nitrogen. So, eating bugs is their source of nitrogen, too.
How old is the world's oldest tree and how do we know?
The oldest tree in the world is a bristle cone pine tree, and it's found in California. It's 4,600 years old. Trees can have their age determined by counting their rings. Now, there's an annual growth ring around the outside of the tree, and every year that ring produces another ring. And so if you just go back and count the rings, and you can do that either by cutting the tree down, which is not recommended, or you can take a core sample, which pulls out the rings from the center of the tree. This technique will also actually tell you the weather of certain years, because in the years where there's a lot of moisture, a lot of rainfall, the ring will be much bigger. And in the drier years, the ring is smaller. So you can not only tell the age of the tree, but also past climatic events.
Why does fruit ripen?
Fruit will ripen because there are some chemicals inside the fruit itself called catalysts. And these catalysts will cause the starch that is in there, inside the fruit, which is basically stored food for future plants. But that will be turned from starch into sugar, and that's basically the ripening process behind the fruit. As starch changes to sugar, it goes from a kind of a bland taste to a sugary sweet taste. And you can even experience this if you take a cracker, which is basically starch, put it in your mouth, and just chew it until you can't anymore. You will notice that over time the cracker begins to taste sweet.This is because the enzymes in your mouth are actually taking the starch in the cracker and changing it into sugar.
Are tomatoes fruits or vegetables?
Are tomatoes fruits or vegetables? Man, that's a question that comes up so often. Some people look at a tomato and they say, “That's a vegetable.” And some people say, “No, that's a fruit.” Well, basically, if you look at the biology end of this that a tomato is a fruit because a fruit is actually the organ of the plant that is involved in reproduction and the tomato produces the seeds so it is a fruit. A watermelon is a fruit but we call them a vegetable. So we are getting mixed up between the grocers' definition of fruits and vegetables and the scientists' definition of fruits and vegetables.