Name: ____________________________________________

gram stain kitBacteria Study (Web)

In this activity, students will use resources found on the web to gain an understanding of how bacteria are stained and classified. Students can use this activity as a pre-lab or to supplement a unit on bacteria and pathology.

First of all, review the steps for Gram Staining at WikiHow

1. Who developed the Gram Stain technique?


2. Why is gram staining important for classifying bacteria?


3. Summarize each step of the technique (do not copy, try to condense each step into 3-5 words)



4. Compare gram negative bacteria to gram positive bacteria (focus on the details of the cell wall.)


Check out these videos on Gram Stains to get a very clear idea of how you will be doing one in the lab.

Youtube: Gram Stain | Youtube: BEST Gram Staining Video Ever!!!

5. What is the purpose of passing the slide with the bacteria specimen through the flame of a bunsen burner?


6. What are the chemicals used in the staining process?


7. Based on the instructions and videos, what are some precautions that should be taken during the gram staining technique



Anatomy of Prokaryote Cells

Review the prokaryote at
You only need to review 1. Overview , 2. Morphology, and 3. External Structures

1. What is the main difference between a prokaryote and eukaryote cell?



2. Sketch and label the three main shapes of bacteria.



3. What is the difference between staphylococci and streptococci?



4. What are the three shapes of spiral bacteria?



Bacteria Images

Locate each of the following organisms using PHIL (Public Health Image Library). If you cannot find the information on PHIL, use a google search.

*Due to the difficulty of typing the words, you might want to open this page in another browser window so that you can copy/paste.

**Warning: some images are inappropriate for young viewers**

Organisms Gram
(+ or -)
Shape Sketch Disease, condition, or general info
Neisseria gonorrhoeae        
Staphylococcus aureus        
Clostridium perfringens        
Staphylococcus pneumoniae        
Staphylococcus pneumoniae        
Bacillus influenzae        
Escherichia coli        
Legionella ( Mycobacterium tuberculosis)        
Candida albicans        
Micrococcus luteus        
Bacillus anthracis        
Staphylococcus epidermidis         
Clostridium botulinum        
Yersinia pestis        
Clostridium tetani        
Treponema pallidum        
Mycobacterium tuberculosis        
Vibrio cholerae