Biology—Semester A

Let's get cellular.

  • Credit Recovery Enabled
  • Course Length: 18 weeks
  • Course Type: Basic
  • Category:
    • High School
    • Science

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Shmoop's Biology course has been granted a-g certification, which means it has met the rigorous iNACOL Standards for Quality Online Courses and will now be honored as part of the requirements for admission into the University of California system.

This course has also been certified by Quality Matters, a trusted quality assurance organization that provides course review services to certify the quality of online and blended courses.


To life, to life! In Semester A of this Biology course, we lift our soda bottles to the study of life. L'chaim!

Chances are, you've heard of cells, genetics, and evolution. After all, you can't watch the news or any show on Hulu without hearing about stem cells, DNA evidence, or the controversy over evolution. But can you tell us:

  • how plants manage to get energy from the sun?
  • how a blond-haired kid can be born to a brown-haired family?
  • why exactly carbs are not the evil enemy the media has made them out to be, but the one molecule essential to human survival?

Our lessons, glossaries, readings, and activities could help you out there, dontcha think? Tagged with the Next Generation Science Standards, our Biology course has everything you need to make science your biomass.

P.S. Biology is a two-semester course. You're looking at Semester A, but you can check out Semester B here.

Required Skills

Knowledge of basic pre-algebra concepts


Unit Breakdown

1 Biology—Semester A - Introduction to Biology

In this introductory unit, we'll answer the big questions of life. No, really. We'll ask, "Do you even lift, bro?" Actually, this unit is about the other big question, "What is life?" You'll also get comfortable with other big issues in biology, including ye olde scientific method and how biological systems are organized.

2 Biology—Semester A - The Chemistry of Life

What better way to get acquainted with biology than through...chemistry? That's right. When it comes to life, it's chemical all the way down. (We haven't confirmed how far the turtles go down, but it's pretty far.) In this unit, we'll go straight to the bottom of the biological pyramid by learning some foundational concepts, including atomic bonding, the properties of water, and macromolecules.

3 Biology—Semester A - Cells

Movin' on up the biological pyramid, we come to the smallest unit of life: the cell. This unit covers the properties and components of eukaryotes and prokaryotes, enzymes, osmosis and diffusion, and everyone's favorite cellular process: mitosis.

4 Biology—Semester A - Biochemical Pathways

The phrase "biochemical pathway" sounds like the driest, most boring thing ever, but it's actually a topic near and dear your stomach. It's the process by which our nom-noms are broken down by our cells into energy. This unit covers the basics of cellular respiration (aerobic and anaerobic style) and plants' superpower, photosynthesis.

5 Biology—Semester A - Genetics

Peas changed the world. True story. In this unit, we'll find out how Gregor Mendel discovered genes, and indirectly founded the field of genetics, by observing peas. You'll get cozy with alleles, meiosis, Punnett squares, genetic disorders (well, not too cozy), and other genetics issues.

6 Biology—Semester A - Molecular Genetics

Our quest to gain total genetic mastery continues in this unit with DNA, the molecule of inheritance. Replication, transcription, and translation will make their appearances here, culminating with some discussion of biotechnology. Mwa ha ha...! Er, pay no mind to that mad scientist cackle. We totally don't have any plans for creating a race of super apes.


Recommended prerequisites:

  • Pre-Algebra I—Semester A
  • Pre-Algebra I—Semester B
  • Pre-Algebra II—Semester A
  • Pre-Algebra II—Semester B

  • Sample Lesson - Introduction

    Lesson 2.03: Properties of Water and Hydrogen Bonding

    Ahhh, water. It's deliciously crisp in the form of ice cubes on a hot summer day, yet satisfyingly smooth on a Slip'N Slide. Here's a factoid for you: the bigwigs at the FDA recommend that women drink 2.2 liters of water every day. That's over a half gallon of water. Guys, you're not off the hook. Head on down to the river with your jug and chug, chug, chug, because you are supposed to have 3 whole liters of water every day.



    Or just jump in. That works too.
    (Source)

    Our complex bodies are 60% water and 40% awesome. All right, "awesomeness" isn't a physical property, but the water percentage is still true. And thank goodness that water has such great bonding and cohesion properties, or else we'd probably be a pile of goo on the floor. Hydrogen bonds are one of the main properties making you, well, you.

    Why water? Why can't we be made of 60% Sprite or Gatorade? What makes water so special? We'll answer all these questions and a couple more. This lesson will drench your brain in cool and amazing factoids about water; just don't forget to stay hydrated with the real stuff, too.


    Sample Lesson - Reading

    Reading 2.2.03: So What Is Water's Secret Power?

    We're not finished with water yet, friends. Head over to this Shmoop learning guide to get all the deets on water. We're about to discover how the properties of water all boil down to pretty much one thing: hydrogen bonds.

    As you read, keep in mind the overarching questions of life. No, they have nothing to do with homecoming or 42—or do they? Here are a few questions to think of while you read:

    • What is it about water that gives it many of its special properties?
    • What makes hydrogen bonds so different than other covalent bonds?
    • What role do hydrogen bonds play in the five special properties of water?

    Now that you're done reading that learning guide on water's unique properties, take a look at these last two resources. Not only does water having an amazing secret power (hydrogen bonding of course!), but it also is essential to life for other reasons. While you check out these links, be sure to think about why water is important and essential to life on earth.

    • Water and Life
    • USGS Water Facts. (Once you read all the bullet-point facts about water, use the menu on the left to go to the sections called "Water, the Universal Solvent," "Cohesion and Adhesion," and "Density and Weight." Feel free to click on any of the other sections about water that interest you if you want, although it's totally optional.)

    Just a little hint (because we like you), you will definitely want to read all of these passages and use them to answer the questions in the next activity. You're welcome.

    Oh, and here's a little quickie video asking about water's properties. Take a peek if you like a little audiovisual in your topic reviews.


    Sample Lesson - Activity

    Activity 2.03a: Diamond in the Rough: Does Water Qualify?

    We know you're wondering, why in the world would anyone devote so much time to figuring out plain ol' water. After reading a little about water, you've probably noticed it is a molecule with quite the personality.

    Use your knowledge, notes, and the resources from today's readings to answer the following questions. When you answer these questions, load them up with at least 3–5 sentences of knowledge, if not more.

    1. What are the 5 primary properties of water that make it so special?

    2. For each of these 5 properties of water, explain how it is different than the properties of other liquids.

    3. For each of these 5 properties of water, give a real-world example of how it helps support life.


    Sample Lesson - Activity

    Activity 2.03b: The Dirt on Water

    Have you thanked water lately for helping to keep you alive? Probably not. We know we, at least, don't think much about that big gulp of water we take after our 5K run.

    Basically, life is found wherever there is water. This is due to its incredible properties. Consider Mars. When water went bye-bye, so did life. Sorry, Martians.

    So for this activity, we're going to write haikus about water. Just kidding! We're actually going to check out a virtual lab that lets us see how hydrogen bonds work in water as the temperature varies.

    Go to this page, and click on the play button to watch the water molecules dance.

    • You'll notice that dotted lines appear when the molecules get close. These are the hydrogen bonds.
    • Click on the "Show partial charges" box.
    • Now play with the "Cool" and "Heat" buttons to change the temperature. Observe what happens as the temperature reaches the two extremes.
    • If it helps, click on the "slow motion" box to see how the molecules move and how the hydrogen bonds form.

    Once you're familiar with the simulation, answer the following questions. Keep the simulation open, though. You may need it for reference.

    1. What is the shape of the water molecules?

    2. What atom(s) in the molecule takes on a partial positive charge?

    3. What atom(s) in the molecule takes on a partial negative charge?

    4. What parts/atoms of the water molecules interact to form hydrogen bonds?

    5. What happens to the water molecules as the temperature increases? How does this affect the formation of hydrogen bonds? How do you think this is reflected in real life water as we heat it up?

    6. What happens to the water molecules as the temperature decreases? How does this affect the formation of hydrogen bonds? How do you think this is reflected in real life water as we cool it down?


    Sample Lesson - Activity

    Activity 2.03c: Let's Dish on H2O

    Which property of water do you think is the most important to life? Is there a particular property of water that all life hinges on? For this activity, you are going to post an argument on the class discussion board on why you think a particular property of water is more important than the others.

    Your argument—and it shouldn't be a nasty, turn-a-table-over argument, but more a positioned, even-keeled stance on a topic—should consist of the following:

    • A clearly defined property of water, including a 1–2 sentence explanation of what it is. (Imagine you're explaining it to a stranger who has no idea what water and its properties are.)
    • A 3–5 sentence paragraph discussing why this property is important in regards to water. How does it affect water? How does it determine the role of water on the Earth?
    • Lastly, add 1–2 sentences talking about why this particular property is more important than other ones. Does it impact humanity more? Is it the deciding factor on whether something lives or dies?
    • Just to be clear, you should be writing a total of 5–7 sentences in your post. It's supposed to be a beefy paragraph, so don't give us the 90% lean version. We want the full-fat paragraph.
    • There are no right answers here, so get creative with your argumentation.

    Once you post your argument, comment on at least two other students' posts. "I agree" does not qualify as a comment, so get down and dirty with the argument. Got a counterexample? Shout it from the rooftops. Have some more evidence to back up another student's claim? Step in and put it on (virtual) paper. Each of your counterarguments needs to be at least 2–3 sentences. And no, "I don't agree" does not count as a full sentence (even though, technically, it is).


    Sample Lesson - Activity

    1. Which of the following is not a special property of water?

    2. Which of the following properties enables water to be an effective solvent?

    3. Water is an effective buffer because of which of the following characteristics?

    4. Which of the following properties of water helps moderate Earth's temperature?

    5. Which of the following is true regarding the polarity of a water molecule?