Characteristics of Living Things

What does it take to be a living organism?

Living things share eight characteristics (listed in Chapter 1 of your textbook on page 19). A living thing grows, undergoes metabolism, responds to its environment, reproduces, passes DNA to the next generation, maintains homeostasis, changes over time, and is made up of cells. A nonliving thing may seem to do one or more of these things, but to be classified as living, all eight characteristics must be present. Sometimes, you may see something that seems alive but is not. Water, for example, moves, responds to temperature, dissolves substances, erodes rocks, and so on, but it does not have DNA and is not made up of cells. Other times, you may see a thing and think it cannot be alive, yet it is. Coral looks like a rock, but a coral reef is actually made up of millions of tiny animals.

Focus your discussion on only 1 of the following topics:

• Choose a living organism, and explain how it illustrates each of the characteristics of life.
• Research and describe an organism or cell in which all 8 characteristics are not obvious. For example, coral looks like it does not move, red blood cells do not reproduce and have no DNA, frogs freeze in the winter and it therefore seems as if they do not maintain homeostasis, and so on. Describe the missing feature, and explain how this organism still meets the criteria of a living thing.
• Compare a living thing with a nonliving thing of your choice that has some of the characteristics that define life. For example, a car exhibits metabolism (burning gas and producing heat), a characteristic of life, but is not alive because it cannot reproduce.
• Compare and contrast the following pairs based on the 8 characteristics that define life:
  • A rock and a snail
  • A lamp and a tree
• Discuss some of the characteristics that fire shares with living things (it can grow, it metabolizes, and so on).

Utilize at least 1 credible source to support the arguments presented in your post.