<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />
Skip Navigation
You are viewing an older version of this Concept. Go to the latest version.

Characteristics of Life

Outlines the five characteristics that are used to define something as "alive."

Atoms Practice
This indicates how strong in your memory this concept is
Practice Now
Turn In
Little Packages
Teacher Contributed

Little Packages

A crosssection of a pumpkin (Cucurbita sp.) stem. How many different kinds of cells can you see?


Cells as the basic biological unit

Student Exploration

Teeny, Tiny and Slick

A cell can be a small compartment of any type. Perhaps the best known cells are prison cells. They show up on television all the time and are generally considered to be rather unpleasant places. But they are not the only type of cell or even the most common. In biology, one of the most basic units of organisms is the cell. A small compartment with everything a living organism needs, more or less. Organisms can consist of a single cell or be multicellular (i.e. made of multiple cells) and in multicellular organisms some cells can become so specialized that they don't quite have everything they need to go solo. But that's not the cell's fault, that's just what works best for the organism. The cell? Well, they're pretty sophisticated in all they can do, they are little bundles of phospholipidized dynamite. Find out more from a man who knows his cells, Sir Paul Nurse.

Extension Investigation

  1. What did Sir Nurse mean when he said,"Technology begets discovery"? Can you think of other advances in biology that technology has made possible?
  2. Who was the first person, that we know of, to see single celled life? Where did he acquire these organisms?
  3. Sir Nurse compares the biological cell to the physical atom. Do you think this is a good comparison? What strengths does this comparison have? What weaknesses does it have?
  4. What point did Rudolf Virchow feel was important to make about cells? Why do you think he felt this was an important point to make? Can you think of other areas where this distinction is important?

Resources Cited

Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes
Please to create your own Highlights / Notes
Show More

Image Attributions

Explore More

Sign in to explore more, including practice questions and solutions for Characteristics of Life.
Please wait...
Please wait...