Video Transcript: Hierarchy of Life

Hi. It's Mr. Andersen. Today I'm going to talk about the hierarchy of life.

Biology is organized from the very small to the very large, which would be the biosphere. And so each of these different levels is called a system. And a system is separated from its surroundings using a boundary. And so for a non biological example, if we have a city, that would be a system. Inside that we have a school; inside that we have a classroom. And so it's kind of like these Russian dolls with the larger ones, enveloping the small ones. And so as we move through these hierarchy of life, one term that I want you to keep in the back of your head is emergent properties. In other words, with each level, as we get to a level, there's going to be a property or properties that show up that weren't there on the level before.

And so let me give you an example. This right here is a soldier this would be a termite protecting the mound. But each of these termites inside are an individual system of their own. They're working together in a system of a colony, and they're actually farming a little fungus that grows within the termite mound. If we even look at a larger scale, this right here is a termite cathedral. Now a termite Cathedral is so big that it faces a major problem. Carbon dioxide is going to build up on the inside of these as they're all doing cellular respiration. And so they could all asphyxiate if there wasn't some way to remove that. And so they're designed so that as the wind blows, there's ventilation and we can actually sweep that carbon dioxide away and new oxygen in its place. Now, you might think, wow, smart termite, how did they figure that out? Well, basically think of it as at different termite cathedrals that are a little bit smaller. And in some of those, all the termites die while their genes would die with them. And those that have any kind of ventilation are going to be able to survive. And so we get a emergent property showing up. So here it is your hierarchy of life from Adam all the way to biosphere. And if you're good at biology, you'll just simply memorize these.

Let's start with the first one, which is not really biology at all, this is an atom, this is an important atom called carbon, because it has four valence electrons. And so it's very good at bonding. If we go to the next level, that would be the molecule. And so here's carbon again. But it's bonded to two oxygen molecules. And so now it's carbon dioxide. What would be an emergent property? Well, that would be the idea that it's more stable, it's actually formed, and it's sharing these electrons. And so it's now bonded. And so that would be something that we find in molecules go to the next level, we have what are called macromolecules, or large molecules. The four different types, remember, are carbohydrates, proteins, lipids, and nucleic acids. An emergent property in them is that they're built of monomers. So repeating blocks, and they eventually show what's called polymerization. Next, if we go, we get to the level of the organelle, these are going to be the tiny organs inside cells, this word here would be the plasma membrane, it's made up of macromolecules. It's made up of this phosphate group on the top, and it gives it this emergent property, the ability to separate the outside and the inside of a cell.

Speaking of cells, this would be a red blood cell, a red blood cell is going to have that plasma membrane inside it. But it's also going to have the hemoglobin protein that I just showed just a second ago. And so now it's emergent properties that it can move around, and it can actually grab oxygen and then move that to different parts in the body.

Next, we go to the level of the tissue, a tissue is made up of a bunch of cells that are working together, this is actually a muscle cell, you can see that there are some striations in it, and we look down here we can see these intercalated discs. And so we know that this is cardiac muscle. And so it does a specific function, which is contract to beat your heart, but it also can receive nerve signals. And so that nervous signal can kind of wash it across it.

Okay, when you have a bunch of tissues that are organized and working together, we have what's called an organ, and this one is called the heart. Now this is going to have all four different types of tissues inside it: it's going to have muscle tissue, nervous tissue, connective tissue, it's going to have epithelial tissue on the inside. And so all those tissues are working together with a single purpose. That heart is sitting inside what's called an organ system. And so this would be the circulatory system. Here we have our red blood cell, but we also have the heart and all of these arteries and veins and they're working together to move that red blood cell around your body.

Next, we have an organism This is called an elk. And elk is made up of a number of organ systems that are working together. Organisms are organized into a population. So this would be all of the elk that are living in one area at a time. Once we get a number of different organisms living in one area at one time. Now we have all these interest species interactions between you know bull elk and cow elk. And so basically this would be an emergent property we find at the level of a population. Next we have all of these different populations interacting together. And so this would be a community. It's all biotic at this point. So they're all living things, but we're going to have this: looks like predation right here. This would be predation. We're going to have you know, competition. And so we have all these interactions between different populations at the level of a community.

Next, we go to the level of the ecosystem. I happen to live right here, right on the border of one of the greatest ecosystems in the world, the Greater Yellowstone Ecosystem. What have we added when you get to the level of an ecosystem? Now we're adding a biotic material. So we're adding water, we're adding chemistry, we're adding light. And all of these things go together to form an ecosystem. Interesting. Where do we put this boundary? Well, basically, they discovered the Greater Yellowstone Ecosystem, the way they figured out the boundaries, they looked at wherever grizzly bears are found. And we said, this is going to be that ecosystem.

Now we go to the level of a biome, a biome is going to be ecosystems that have similar climate, so they're going to have the same temperature and they're going to have the same precipitation throughout the year. And so tropical rainforest or desert, or this would be a Northwestern coniferous forest, or the tundra or the tiaga. And so these are all types of biomes and the biomes together form what's called the biosphere and the biosphere on our planet is wherever we find life, and that goes from deep in the ocean to high in the atmosphere. And that is the hierarchy of life. So I hope that's helpful.