Common Bacteria-Apologia Biology

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There are three basic bacterial shapes.
Coccus is spherical in shape, bacillus is rod-shaped, and spiral bacteria are spiral-shaped.
A pleomorphic bacteria is a combination of several shapes.

Diplococci.

We will start with cocci.  These bacteria are usually elongated, oval, or even flattened on one side.

The cocci remain in pairs after they divide.  These are called diplococci.

The cocci that divided remain in groups of four and are called tetrads.

The cocci that divide into three groups remain in the cube groups as do the groups of eight which are called sarcinae.

Cocci that divide into multiple groups form clusters called staphylococci.

Link streptobacilli

Next up are the bacillus.

These are rod-shaped.

These are usually single rods but diplobacilli appear in pairs after division.

The streptobacilli appear in chains after division.

Great link here.

Lastly are the spiral-shaped bacteria, spirillum.

Spirillum are stain gram negative-i.e. a class of bacteria that do not retain the crystal violet stain that is used in the Gram-staining process which makes identification possible.

Movement by spirillum happens via flagella located at both ends.

Treponema pallidum (syphilis) is the most common spirillum that affect humans.

Resources:
Khan Academy/Crash Course biology with Hank Green
kids health
more on gram staining 
bacteria on Pinterest