Introduction to Biology

In your first lesson, you'll get an introduction to the smallest living part of you: the cell. You'll discover the properties of life that you and your cells both have, and you'll see how cells combine to form the tissues and organs that make up your body. The lesson will also introduce the non-living components that make up cells, including molecules and atoms. Then you'll see how scientists sum up the most important facts about cells in cell theory. By the end of this lesson, you'll know why cells are the smallest units of life, and you'll understand how they make up all living things, including your body.

In this lesson, you'll take an in-depth look at your cells and how they function. You'll consider why all life on Earth is based on cells. You'll take a look at the structures found in eukaryotic cells—the type of cells shared by you, other animals, plants, mushrooms, and seaweed—and explore how each structure contributes to the life of the cell as a whole. By the end of this lesson, you'll have a better understanding of how your cells work.

In this lesson, you'll discover the fundamental units of matter that make up the structure of every organism and the Earth itself. You'll explore the structure of atoms and learn about the attractions that form between atoms to create molecules. You'll also take a peek at the unique nature of the water molecules that cover 70% of the Earth's surface and flow within every living thing. By the end of this lesson, you'll have a gained a foundation in simple chemistry that will help you better understand symbols like H₂O and CO₂. You'll also have a basis for understanding more complicated molecules like carbohydrates, proteins, and DNA.

In this lesson, you'll take a good look at the molecules that make up most of your body. You'll examine the structure of carbohydrates, lipids (fats and related molecules) and proteins, and learn exactly why your body needs all three of these types of molecules. By the end of this lesson, you'll have a better understanding of the value of carbohydrates, the difference between dangerous saturated fats and healthy unsaturated oils, and why you should choose lean protein to get your essential amino acids.

In this lesson, you'll explore the structure and function of one of the cell's most crucial parts: the plasma membrane. All life depends on this very important boundary between a cell and its environment! You'll start by examining the membrane's components and unique properties, which are perfectly suited to protecting the health and well-being of the cell. Then you'll take a look at the important jobs the membrane does for your cells, including screening materials, moving stuff in and out of the cell, and receiving messages. Finally, you'll see how materials cross the plasma membrane and why that's important to normal health. Along the way, you'll gain a better understanding of blood types, diabetes, and cystic fibrosis.

A new session of each course begins each month. Please refer to the session start dates for scheduling.​

Once a course session starts, two lessons will be released each week for the 6 week duration of your course. You will have access to all previously released lessons until the course ends. You will interact with the instructor through the online discussion area. There are no live sessions or online meetings with the instructor.

The interactive discussion area for each lesson automatically closes two weeks after each lesson is released, so you're encouraged to complete each lesson within two weeks of its release. However, you will have access to all lessons from the time they are released until the course ends.​

Students enrolled in a six-week online class benefit from a one-time, 10-day extension for each course. No further extensions can be provided beyond these 10 days.​