General Biology

Learn the toughest concepts covered in Biology1&2 with step-by-step video tutorials and practice problems by world-class tutors

1. Introduction to Biology

Life's Organizational Hierarchy

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concept

Life's Organizational Hierarchy

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So from our previous lesson videos, we already know that one of the eight characteristics of life that all living organisms share is organization. And so here in this video, we're going to talk about life's organizational hierarchy. Now, life actually consists of multiple parts that are organized into a hierarchal pattern and will be able to see this pattern down below in our image. Now, at the smallest scale of this organized pattern, all life is composed of Adams. And at the opposite end, at the largest scale of this organized pattern is the biosphere, which again will be able to define down below in our image. And so if we take a look at our image, noticed that we have this big table here in the middle and it has these three columns and the first column. What we have is the name of the level, the hierarchal level of organization in the middle. What we have is a description of the level and then on the far right. What we have is an image that complements the description. And so notice that over here on the far left, what we have is this scale and so you can see that we're starting at the smallest scale, which again we define as the atoms. And we're building our way up to the largest scale, which we have at the bottom, which again is going to be the biosphere, which we can go ahead and fill in here. But first, let's go ahead and start at the very top and work our way downwards and so again at the smallest scale, what we have, our Adams and all matter, all living things and non living things that take up space are made of atoms. Now, later, in our course, we'll talk mawr about Adams and talk about the basic chemistry that you guys need to know for this course. But for now, we're defining Adams as the smallest particle oven element, and here we have an image to represent an Adam. Now, if you take multiple atoms and you put them together, you can start to build an organizational hierarchy here. And so taking multiple atoms and linking them together can allow you to build molecules, and so molecules are defined as a combination of atoms. And so, for example, we have a water molecule over here, which is H 20 So we noticed we have these two hydrogen atoms and this one red oxygen atom. And by combining these three atoms together, we can build a molecule. And so we can have small molecules that are on Lee made up of three atoms. But we can also have very, very large molecules that are made up of thousands of atoms. Now, these molecules, if we take multiple molecules and we put together multiple molecules, we can build organelles and organelles, kind of sound like organs that air found in cells. And that's pretty much exactly what they are. They're tiny little organs that air found inside of cells, and so we can define them as specialized structures found within cells. And so, for example, we have these two organelles that we're showing you right here, and we'll talk a lot more about organelles later in our course. But just for you guys to know if you're curious, this is the Golgi apparatus and this is the mitochondria. And we'll talk about these organelles again later in our course in a different video. But if we take multiple organelles and we put all of these organelles together, we can actually build cells or a cell. And so we've already defined cell in our previous lesson videos as the smallest unit of life, it's the smallest thing that we can call a lot. And so notice here we're showing you an image of a cell which, you can see consists of these organelles that air found within a bunch of different types of organelles. Now, if you take multiple cells and you put these cells together, you can get tissues. And so tissues air just defined as a group of cells that perform a specific function. And so notice here in our image, we can see all of these, uh, cells are coming together to create tissues. Now, if you take multiple tissues and put multiple tissues together, you can build an organ, and so on. Oregon is going to be defined as a group of tissues, and these this group of tissues is going to perform a specific function. For example, our hearts or the heart of any organism is going to be an organ. Now, if you take multiple organs and put these multiple organs together, you can build an organ system. And so an organ system is going to be defined as a group of Oregon's that are working together to perform a specific function. For example, the circulatory system is an example of an organ system, and the circulatory system includes our hearts, our blood, our blood vessels and arteries. And so here, what we're showing you is the circulatory system within a deer. Now, if you take multiple organ systems such as the circulatory system, our digestive systems, the nervous systems and so on, you can actually build ah, multi cellular organism or just an organism. And so the organism, we also know it from our previous lesson Videos is defined as an individual form of life composed of many cells. And so here, what we're showing you is a deer, which would be a single organism. Now, if you take multiple organisms multiple of the same type of organisms and you put them together, you can get a population. And so population is defined as all of the organisms of the same species that are living in the same area. And so all of the deer that air found in the same area would be referred to as the deer population. Now, if you take populations of different species, then you could build yourself a community, and so a community would be defined as multiple populations but of different species living in the same area. So, for example, if we take the population of deer and the population of squirrels, then we are considering a community. And so they have to be different, uh, species, multiple populations of different species such as deer and squirrel. Now, if we consider the community along with the non living environment, then we can build ourselves an ecosystem. So the ecosystem is referring to the living community, which would be the biotic portion or with living portion, and it refers to the non living surroundings as well. So it also refers to the A biotics, um, components, and a biotic again is referring to non living. And so if we include not only the deer population and the squirrel population, but we also include the river. Um, like what we see here on, we also include the mountains and the rocks and things of that nature. Then we're including the non living surroundings as well, and that is what we refer to as an ecosystem. Now, if we take all of the ecosystems on our planet Earth, then what we have is the biosphere. And so the biosphere, because it has the prefix bio in it, is referring to the portions off, um, our planet that support life. And so it's referring to all of the different ecosystems on Earth that support life. And so here, what we have is a picture of our planet Earth where you can see the biosphere, which would be again all of the different regions of our planet Earth that support life. And so through getting some practice and reviewing this video, you'll be able to get this biological organization down in no problem. So as we move forward in our course, we'll be able to get some practice applying these concepts, and I'll see you guys in our next video.
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example

Life's Organizational Hierarchy Example 1

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all right. So here we have an example problem that says the image below represents the hierarchy of life. Which of the following shows the correct order for Levels two through four. And we've got these five potential answer options down below. And so if we take a look at our image down below, over here on the right hand side, notice that it does represents the hierarchy of life. However, it is not showing all of the levels of life's organizational hierarchy that we talked about in our last lesson. Video notice that it's starting at the smallest level off organism, and it builds up to the highest level of biosphere. And so it's missing all of the smaller levels of organization that are smaller than organism. However, even though it's missing some of the levels of organization, we still need to make sure that levels two through four here are in the correct order, going from smallest to largest. And so if we take a look at the first level of organization being shown here in this image, it is organism. And so we have one single organism, one single form of life, this one fish being shown here and then in number to notice that we are showing ah group or a collection of the same species of organism because we have the same exact type of fish. And so because we have a group of the same species of organism living in the same area, what this means is that we have a population here now moving on to number three. Notice that it's now starting to show multiple populations with different species of fish. And so because we have multiple populations with different species, this level three here is referring to the community and then notice that moving on to number four in this image, it's starting to show mawr of the non living environment. You can see these rocks, uh, that air being shown here. And so we still have the population, the living biotic environment. We still have these this community of fish, but we are also starting to include the non living environment, which means that number four is referring to the ecosystem. And of course, we know that all of the ecosystems on Earth allow us to get the biosphere, which is the last level, and so we need to select the answer option that reflects the order that we have here where two is going to be referring to the population. Three is the community and four is the ecosystem. And the only answer option that reflects what we just talked about here is answer Option C, which says that, too, is the population. Three is the community and for is the ecosystem, just as we discussed here and so we could go ahead and indicate that option. See, here is the correct answer to this example problem and that includes that concludes this example. So we'll see you guys in our next video where we can get some practice.
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Problem

Which of the following options has the correct order in terms of the hierarchy of the organization?

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Problem

Use the word bank to complete the pyramid of life’s organizational hierarchy below.

Word Bank:
Population
Organelles
Organ System
Cell
Tissues
Ecosystem
Organ
Community
Molecules
Multicellular Organism

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5
concept

Emergent Properties

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in this video, we're going to introduce emergent properties and so, emergent properties as their name implies, our properties that emerge or arise upon combining smaller parts together. However, the individual, smaller parts when they are separate do not display the emergent property. It's only when those individual smaller parts are combined, that the emergent property arises. Now, emergent properties are incredibly relevant to life's organizational hierarchy that we covered in our previous lesson videos. And this is because at each new level of the hierarchy, there is going to be an emergent property that arises. And so the whole is going to be greater then the sum of its parts. And really this is another way to explain emergent properties, combining smaller parts together allows for a new emergent property to arise in the hole. And so the whole will be greater than the individual sum of the parts. And so, to get a better understanding of emergent properties, let's take a look at our image down below. And what you'll notice is the top half of the image here is showing you uh an example of an emergent property. And so notice over here on the left hand side, we're showing you these bicycle parts where you have a tire and pedals and a chain and the bars that go along with a bicycle and notice that all of these parts are separate from one another. And so these are individual, separate bike parts. Now, these individual separate bike parts do not allow for transportation, there's no way that you could uh go very far with these separate individual bike parts. However, when you combine those separate individual bike parts together in a very specific and proper way, then you can create a bicycle that allows for transportation efficiently. And so transportation was not available with these individual separate bike parts. However, transportation is available when you combine these individual parts together and sew transportation here, for that reason is an example of an emergent property in that example. Now, in a very similar way, if we look at the bottom half, you can see how these emergent properties also apply to life's organizational hierarchy. And so notice on the left hand side, uh we have an example, we have these separate individual organelles or organs of cells, such as for example, the Golgi apparatus and the mitochondria. And so these separate individual organelles are not alive. There's no life here because these separate individual organelles do not display all of the characteristics of life. However, when you combine all of the organelles that are necessary in a very specific way, uh similar to how we combined all of the bike parts in a very specific way, uh an emergent property arises of life. And so here, what we're showing you is a cell that contains all of the necessary organelles uh that allow for life. And so life here in this example is an emergent property that arose again, uh moving forward in life's organizational hierarchy to a larger scale. And so again, emergent properties arise at every single level of the scale as you increase uh in that hierarchy. And so this year concludes our brief lesson on emergent properties, and we'll be able to get some practice applying these concepts as we move forward. So I'll see you all in our next video.
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Problem

Which of the following is the best example of an emergent property?

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Problem

At which point of the organizational hierarchy does life emerge?

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