Transcript: "In this opening episode, we are going to explore the different levels of biological organization. In order to study these different levels of biological organization, we will use an approach termed reductionism to reduce complex systems to simpler components that are more manageable to study. This journey begins in outer space. The planet Earth is considered a biosphere of life. The term biosphere means all life on Earth and all the places where life exists including most regions of land, bodies of water, the atmosphere to an altitude of several kilometers, and even sediments far below the ocean floor.
In the next part of this journey, we look at the ecosystems. What comes to mind with the term ecosystem? Is it just plants or animals? Well, this term encompasses much more than that. Ecosystems consist of all living (like animals and plants) and nonliving things (water and sun) in a particular area. An example of an ecosystem is the deciduous forests in North America.
Zooming in from the ecosystems, we can see different biological communities or species living in these ecosystems. Organisms inhabiting a particular ecosystem are termed a biological community or species. The biological community in the deciduous forest ecosystem includes many types of trees and other plants, various mushrooms and other fungi. There are different types of communities for different types of ecosystems.
Within a community, we can observe the population. A population consists of all the individuals of a species living within the bounds of a specified region. What example of a population can we see in an Indiana forest? One example is a population of white-tailed deer.
Our next level of zooming goes to the category of organisms. Organisms are individual living things. Each of these white-tailed deer in our previous example are an individual organism.
The structure of life continues to unfold as we reach the next level of organization, which are organs and organ systems. Organs and organ systems are defined as body parts that carry out a particular function in the body. Specific examples of organs and organ systems include the stomach, brain, and heart of a deer.
Our new friend the deer has many different organs that are composed of tissues. Tissues are the next level of organization that we will see. Tissues are a group of cells that work together, performing a specialized function. Some tissues, like muscle tissues help the deer to move while other tissues, like nervous tissues help the deer to make quick decisions.
Within these tissues, we can find cells. The cell is life’s fundamental unit of structure and function. A single cell performs all the functions of life, while a multicellular organism has a division of labor among certain specialized cells.
Inside these cells, we can find organelles that perform various functions for a cell. For example, the mitochondria are an organelle in the cell that provides energy. In this level of organization, we can see an example of emergent properties. Emergent properties states that at each level of complexity, there are novel properties that emerge that were absent from the preceding one. In this case, we observe the organelle mitochondria that was not present in the tissue level of organization.
Our last stop on this journey of the levels of biological organization is molecules. A molecule is a chemical structure consisting of two or more units called atoms. Within each mitochondria, we can see millions of molecules that are organized into a system that helps produce energy for the cell. So as you can see, the world you live in is much more complicated than the untrained eye would suggest. Biologists use systems biology, or the exploration of a biological system by analyzing the interaction among its parts, to understand these complicated levels of organization."