Ap Bio Lab

DIY - What Is Life?

How can you determine whether something is alive, dead, or non-living?

Whenever we speak of life, we must think in terms of cells. Even though we cannot see cells without a microscope, they are the basic unit of life and they exhibit all of the characteristics of living organisms. They can exist individually, as do bacteria, or they may work together, taking on specialized tasks to create a more complex organism. However, all living organisms share certain characteristics, which are discussed below.

Cells are made of cytoplasm. Cytoplasm is a specially organized solution of salt, nutrients, and complex molecules in water. The composition of cytoplasm may vary among different types of cells, but its purpose is the same – it provides a medium in which complex reactions can occur.

For complex reactions to occur, cells need a source of energy.

However, this determination is not always straightforward. Viruses have some, but not all, of the qualities of living organisms, and scientists have long argued whether or not they should be considered as living organisms.

In this exercise you will determine whether specimens are non-living, living, or dead.

CHARACTERISTICS OF LIFE - STATION LAB
Lab Procedures:
First, observe the specimens located at each station without touching it. Examine their size, color, shape, and even smell (if possible). (Do not taste the specimens.) Then follow the instructions at each lab station for examining the specimen further. As you look at each specimen, ask yourself whether it has some or all of the characteristics of a living organism.
Work with your lab group to compile a list of what you know about each specimen.
Record in your data table all the characteristics your lab group observed that would classify each specimen as living or as nonliving.
Team Data Table
SPECIMEN
CHARACTERISTICS
(LIVING)