Print this chapterPrint this chapter

Week 9 - Characteristics of Living Things

1 Introduction - What is Living?


No Textbook Readings for this lesson



Cells and Systems

The universe is a marvelous place that is filled with stars, galaxies and even collections of galaxies called super-clusters. But through all our investigations of the our own solar system and the milky way galaxy we have yet to find any other signs of life out there. Many astronomers and exobiologists and organizations like SETI and NASA are looking for extraterrestrial life. But how does one define life and what kind of living things might we expect to find out there?
Is there life out there?
NASA's Hubble Space Telescope shows a rare view of a pair of overlapping galaxies, called NGC 3314. The two galaxies look as if they are colliding, but they are actually separated by tens of millions of light-years, or about ten times the distance between our Milky Way and the neighboring Andromeda galaxy. The chance alignment of the two galaxies, as seen from Earth, gives a unique look at the silhouetted spiral arms in the closer face-on spiral, NGC 3314A.

But we don't have to search into deep space to find strange life forms. Many scientists believe that we know more about space than we do of the Earth's deep oceans. Come along as we explore some of the strangest living creatures ever seen.
Check out this PBS site and examine creatures like 'fang tooth' and 'viper fish'. Some creatures even make their own light in a world where there is no light . This is called bioluminescence . In this module we will be exploring some of the concepts we have about life. Like all investigations in science we will start off with some questions to focus our investigations.
  • What defines something as living?
  • Do all living organisms have things in common?
  • There are about 1.75 million species on Earth. How do we make sense of the vast diversity of living things we find on this planet?
  • What variations in structure and function can found in living things?
  • Finally, and more personally, how does our body work?
Now these are the kinds of questions that keep whole communities of biologists busy, so we'll only be able to scratch the surface here. We hope you enjoy this module. Perhaps you may become the astronomer, exobiologist, or marine biologist that finds new life 'out there'.

Lesson 1

Lesson 1: What is Living?

"I think therefore I am"
Rene' Descartes (1596-1650). The father of modern philosophy.

The computer can perform more complex mental tasks then the baby and yet we know that the baby is alive and not the computer. Obviously there is more to being alive then simply thinking.

Background Information

All living things :
  • are made of cells
  • grow and develop
  • need energy
  • respond to their environment
  • reproduce
  • adapt to their environment

Exercise 1.1: Characteristics of Living Systems

Use the Internet to research and locate a current or recent study of an animal found in your area.

Optional: Include an "interesting facts" section on the animal you study. 

If you are in Alberta the following resource may be useful: 
Fish and Wildlife: click here

 1. Describe how the animal meets the last five of the characteristics of living organisms (omit the first item as all plants and animals are composed of cells).

© 2002 Alberta Online Consortium