Name:________________________________Period:___ Date:______________
#:_____
Classifying Bacteria
Problem: How are bacteria classified?
Procedure:
Look at the pictures of bacteria in the data table. Use the table and to help you complete this exercise.
Follow the directions in the dichotomous key to identify each bacterium. (Remember, you always start at #1 no matter
which bacteria you’re identifying.)
Dichotomous Key:
A
AA
AAA
Shape is cocci
Shape is baccili
Shape is spirilla
Go to B
Go to C
Treponema pallidum
B
BB
BBB
Bacteria are in pairs
Bacteris are in chains
Bacteria are in clumps
Go to D
Go to E
Staphylococcus aureus
C
CC
CCC
Bacteria are in pairs
Bateria are in chains
Bacteria are single
Bacillus anthrcis
Bacillus lactic
Go to F
D
DD
Bacteria have extra membranes (Gram -)
Bacteria lack extra membranes (Gram +)
Diplococcus meningititdis
Diplococcus pneumonia
E
EE
Bacterium is large
Bacterium is small
Streptococcus pyogenes
Streptococcus lactis
F
FF
FFF
Bacteria has flagella
Bacteria has a spore in its center
Bacteria has a spore in its end
Bacillus typhosa
Bacillus botulinum
Bacillus tetani
(Write the name of the bacteria in the box below its picture)
Name:________________________________Period:___ Date:______________
#:_____
Classifying Bacteria
Questions and Conclusion
1. What scientific term is used to denote the
a. round shape?______________________________
b. rod shape?________________________________
c. spiral shape?______________________________
2. Identify by scientific name the bacteria associated with the following:
a. Pneumonia______________________________________________
b. Botulism poisoning________________________________________
c. Tetanus _________________________________________________
d. Anthrax_________________________________________________
3. What to the following prefixes mean?
a. Diplo________________
b. Staphylo_____________
c. Stepto_______________
4. Why is in important to be able to identify the different types of bacteria?
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5. Some species of bacteria have endospores, or spores. These spores inside the bacteria contain an extra copy of
the bacteria’s DNA surrounded by a tough outer covering. When environmental conditions are not favorable,
the endospore is able to withstand the conditions until they are favorable again. When conditions are better,
the spore uses the DNA inside to make a new bacteria cell. Why is this important to the bacteria cell? Are these
cells ‘immune’ from natural selection? Why or why not?
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6. Knowing what you know about prokaryotes and bacteria, draw a super bacterium, one that would be able to
survive anything: environmental conditions, antibiotics, etc. What features would it have? Write the features (at
least two) on the line then in the space below draw your bacteria with those features.
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