Characteristics of Life: Is It Alive?

Biology is the study of living things. Scientists have a set of criteria that an organism must possess in order to be considered alive or once living. For example, viruses are not classified as living things because they cannot reproduce without the help of a host. In this activity you will determine some of the characteristics of living things.

Materials

Small animal (such as an ant) in a covered container (handle carefully; release after the activity is done)

Small plant (such as a potted fern or clump of grass)

Rock

Magnifying glass

Activity

1. Think of several different living things. Make a list of all the characteristics you think a living thing must possess to be considered ''alive.''
2. Once your list is complete, look at the ant and the fern and see whether they possess all these attributes. You may want to add to or delete characteristics from your list at this time.
3. Now examine the rock and see which attributes it lacks.

Follow-Up Questions

1. What characteristics did you decide are common to living things?
2. What characteristics did the rock lack that ruled it out as a living thing? Did it have any characteristics that living things also possess?

Answers

1. Answers will vary. Some possibilities include the need for energy and the ability to move.
2. Answers will vary. One possible answer is that rocks are not made of cells.

Extension

Visualize a mushroom and an amoeba. You may need to look these up in a textbook or on the Internet. Do these two organisms meet the criteria for living things that you established? Do you need to add additional characteristics or delete some you established about the animal and plant you observed earlier?