The Basic Nature of Life

The Basic Nature of Life
Coming up next: Comparing the Human Lifetime to the Universe

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:01 What Is Life?
  • 0:55 The Definition of Life
  • 1:43 The Processes of Life
  • 3:00 Evolution, Selection, Mutation
  • 5:19 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Lesson Transcript
Instructor: Artem Cheprasov
What is life? This lesson will attempt to define this and what the basic nature of life is on Earth. We'll go over DNA, RNA, biological evolution, and natural selection.

What is Life?

What is life? This is a question I will not be able to fully answer for you, although I'll attempt to define it later. Even among living creatures here on Earth, what life actually is, is still a matter of nuanced debate. For example, some people are still debating whether viruses are technically alive or not. If we can't settle the debate here on Earth, we may not be able to recognize very different life forms on other planets, even if they hit us in the face.

Other lessons will explore the possibility of life on other planets, but this lesson will focus on establishing some key basics about the nature of life right here on Earth that are not in question so we can later compare that to potential life in the far reaches of the universe.

The Definition of Life

If I were to attempt a definition of life, as evidenced by processes here on Earth and Earth alone, I would say it goes something like this: life is a process which involves the metabolism, growth, and reproduction of an organism and that organism's manipulation of and adaptation to its surroundings for its survival.

The basic nature of all life on Earth includes some key underlying features, such as carbon. We are carbon-based life. But carbon alone is not nearly enough to actually account for the definition of life I gave. A lump of carbon is as good as a lump of coal. There has to be more than that, obviously.

The Processes of Life

Remember, life is a process. For a process like metabolism to occur, there have to be actions that are carried out. For actions to be carried out, there have to be instructions for those actions.

It's like a manufacturing plant where something like a TV is made. The process of making a TV involves actions performed in an assembly line by a lot of different people and even robots. But those people and robots need instructions for their actions. People are told what to do with written or spoken words. Robots are told what to do via computer code.

Our body's computer code, which accounts for the processes in your body that help you grow and keep you alive, is based namely on DNA, deoxyribonucleic acid, although RNA, ribonucleic acid, plays an important role, as well. The instructions involved in life, DNA, must be passed down to offspring during reproduction. Sort of like a plant manager may copy her instructions to a colleague to pass along to someone else. When reproduction occurs, DNA is copied down for the next generation.

Evolution, Selection, Mutation

But life isn't just about metabolism, growth, and reproduction. The definition includes a life form's adaptation to its surroundings. This is critical for life. If DNA, our body's computer code, couldn't change over time, we wouldn't be here today. If a computer company's computer engineers didn't change the code for their software, they would be out of business because times change and the computer company has to adapt with the times.

Times change in real life as well, not just virtual code. The way in which life adjusts over time to external (that is to say, environmental) changes is one way to define biological evolution.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create An Account