Chapter 4

Indicate the size ranges in bacteria in comparison to other organisms.

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Name three bacteria that form endospores.

1. Bacillus (e.g. bacillus anthracis aka anthrax) 2. Sporosarcina ( 3. Clostridium

What are the arrangement of bacteria based on?

Arrangements of cells are based on the number of planes in which a give cell type divides.

Describe the shapes of bacteria and their possible variants.

Most bacteria have one of 3 general shapes based on configuration of cell wall: 1. coccus (sphere) 2. bacillus/rod (cylindrical) - vibrio (gently curved) - coccobacillus (short & plump rod) 3. Spiral (corkscrew shaped) - spirillum (rigid helix) - spriochetes (flexible helix)

Are endospores used for reproduction? Explain your answer.

No, because no increase in cell numbers is associated with its formation.

What is the medical significance of bacterial spores?

When the spores of cetain species are embedded in a woud that contains dead tissue, they can germinate, grow, and release potent toxins.

Identify several arrangements of bacteria and how they are formed.

cocci - Division in one plane: singles->diplococci (pairs)->streptococci (chains) Division in tow perpendicular planes: singles->tetrads (packets of four)->sarcina (packets of 8-64) Division in several planes: singles->staphylococci and micrococci (irregular clusters)