The Wonderful World of Microbiology Quiz

Answer: cell wall

Gram positive bacteria have a thick peptidoglycan cell wall, and Gram negative bacteria have a thin peptidoglycan cell wall with an outer membrane. Gram negative bacteria are also more likely to be pathogenic than Gram positive bacteria.

Answer: plasmid

Plasmids are very useful in genetic engineering, enabling us to insert human genes into bacteria to produce mass quantities of human proteins.

Answer: lipopolysaccharide

LPS induces a fever response in the human body. Gram negative bacteria are often heat-sensitive, so the fever will help to eliminate the infection.

Answer: DNA replication

Okazaki fragments are the small segments of DNA that are formed on the lagging strand during DNA replication.

Answer: Desulfovibrio

The Winogradsky column is a device that models the interactions of bacteria in the environment. Desulfovibrio are sulfate-reducing anaerobic bacteria that live at the bottom of the column.

Answer: iodine

The mordant helps in the uptake of dyes into the cell. Crystal violet is the primary stain, alcohol is the decolorizer, and safranin is the counterstain.

Thanks lateonenight: Iodine is technically not a mordant, but a trapping agent. To be correctly classified as a mordant, a compound must be a metal, which iodine is not. However, most Gram stain procedures refer to iodine as a mordant. For more information on the difference between trapping stains and mordants go to http://stainsfile.info/StainsFile/theory/trapping.htm

Answer: Methanobacterium

Methanobacterium belongs to the domain Archaea, which differs significantly from Bacteria in chemical structure and metabolism. The term "bacteria" is commonly used to refer to all prokaryotes, or single-celled organisms lacking a nucleus.

Answer: penicillin

Mycoplasma has no cell wall, and since penicillins disrupt cell wall synthesis, the antibiotic has no effect.

Answer: F-plasmid

F-plasmid stands for fertility plasmid, although my biology class used a different mnemonic. :)

Answer: extreme cold

Extreme cold, while inhibiting the growth of most bacteria, does not usually kill them. And although heat and high and low pH will kill most known species of bacteria, certain species of Archaea can live in these extreme environments.