Introduction to Biology

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.

In this lesson, you'll learn all about enzymes: what they are, what they do, and why they're important to cells and human health. You'll also get an introduction to chemical reactions and some fundamentals of human metabolism. By the end of this lesson, you'll know why you need vitamins and minerals in your diet. You'll also discover how humans can manipulate enzymes, targeting them in order to benefit or harm human health.

In this lesson, you'll explore one of the most important parts of your metabolism: cellular respiration. Cellular respiration is the process that your cells use to get the energy they need to survive. You'll learn the fundamental laws that govern all energy exchanges, whether your cells or man-made machines perform them. By the end of this lesson, you'll understand the most important events that occur during cellular respiration, and you'll have new insights into why you breathe and why you sweat.

In this lesson, you'll look at the most important molecule of life: DNA. You'll see how the genetic blueprints in DNA determine all of your unique traits. You'll also explore the structure of DNA and learn about its powerful chemical code. By the end of the lesson, you'll know what the letters A, T, G, and C mean to biologists, and you'll have a better understanding of the importance of stem cells in medical research.

In this lesson, you'll explore how cells divide to make new cells for growth, repair, and sexual reproduction. You'll see how cells make exact copies of themselves during mitosis in order to grow or repair damage (such as a paper cut). The lesson will walk you through the process of mitosis to show you how cells get exactly the right number and types of chromosomes. You'll then see how a special kind of cell division called meiosis is necessary for sexual reproduction and the human life cycle.

In this lesson, you'll find out how parents pass traits to their offspring. You'll explore how the genetic information from both parents interacts to determine which traits appear in each generation. By the end of this lesson, you'll have a better understanding of why people in families look like each other and why there is so much diversity in human traits like skin and eye color. You'll also know more about the inheritance of some genetic diseases.

In this lesson, you'll look at how biologists are delving into the mysteries of life by reading and manipulating the genetic code. You'll take a peek at some of the new DNA technology that's helping scientists test for and treat genetic diseases, engineer organisms, and solve crimes. You'll explore some of the issues this technology presents. By the end of this lesson, you'll have a better understanding of genetic testing, genetically modified organisms (GMOs), and how DNA is used in forensic science.

In the final lesson of the course, you'll investigate how normal cells turn into cancer cells. You'll look at the changes that occur in cells as the disease progresses. You'll also explore how cancer treatments work and find out what lifestyle choices you can make to lower your cancer risks. By the end of this lesson, you'll have a better understanding of the biology behind cancer, as well as the risks, prevention strategies, and treatments for this disease.