About this video
Sal introduces the high school biology course by asking us to stop taking life for granted. He points out that we are made of tens of trillions of cells and bacteria working together, and lists the big questions biology tries to answer: how traits are inherited, how cells replace themselves, what mutations do, how life began and where our energy comes from.
You'll be able to
- describe some of the big questions that biology tries to answer.
- explain why the human body is an example of a complex biological system.
- trace where the energy we use ultimately comes from.
Key words
- organism
- A single living thing, such as a person, a plant or a bacterium.
- cell
- The tiny living unit that living things are built from; your body has tens of trillions of them.
- trait
- A characteristic, like eye colour, that can be passed from parents to offspring.
- mutation
- A change or 'mistake' in the information a cell passes on, which can sometimes be harmful and sometimes helpful.
Transcript
- It's very easy to take for granted some of the very amazing things that surround us. In particular, the notion of life. On a day-to-day basis, we're used to it. We are living things, we see living things all around us, and we get preoccupied with other things.
Things like doing our homework, paying our taxes, worrying about what our next meal is going to be. But if you just take a moment, and I encourage you to actually take that moment right now, look in the mirror or look at me in this video. We are miraculous organisms in a miraculous biological system.
Each of us is made of trillions, tens of trillions of living cells and bacteria that somehow organize together to create us and these incredibly elegant and complex systems. How does that happen? How do you get intelligence? How do you get sensory perception? How do you pass on those traits from one generation to another?
How do cells replenish themselves? What happens when there are mistakes? Are mistakes or mutations sometimes a good thing, or are they always a bad thing? How did life even emerge on, as far as we know this planet, maybe other planets? Where do we get our energy from?
It turns out the sun. But then where do we get that energy from because we're not taking that solar energy directly. How do we get it from other things like plants, which are other forms of life? And how is all of this interconnected and related? This is the focus of this high school biology course.
And I just have to say, you know, it's hard, people always ask me, "What's your favorite topic, Sal?" And I'm not gonna say it is hard to pick because it's like picking a favorite child. But if you don't stop and pause and think about the wonder of life around us, then it just makes life a lot less interesting.
And if you just pause for that moment and especially if you start to understand as you're going to do in this course, then I think you'll just have a little bit more wonder and a lot more understanding of how we fit in the universe.
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