Question

The brilliant research scientist, Professor "Iron-Mike" Scrawll is studying a new pore-forming toxin from the pathogenic bacterium Minnesotious goferious, the causative agent of Rusty Rodent disease, which transforms normally docile copper gophers to aggressively attacking the ankles of golfers and stealing their golf balls on the U of I blue course. Professor Scrawll has isolated the virulence factor BurD, which he has discovered to be a very stable, large, pore-forming exotoxin. His research indicates that, when BurD is applied to cultured human ankle cells, the cells are rapidly lysed and die. Excitedly, Professor Scrawll sends a sample of his purified BurD to his colleague, Dr. D. Bogey, who attempts to repeat the same experiment. Disappointedly, Dr. Bogey reports back that BurD did not lyse and kill cultured ankle cells in her lab. After an emergency meeting at the 19th hole, Professor Scrawll and Dr. Bogey hold a press conference to explain the discrepancies in their data. Based solely on what you know about BurD, which of the following explanations most likely explains experimentally why Professor Scrawl and Dr. Bogey obtained different results?
a. Professor Scrawll applied 100 nM BurD to the cells for 12 hours, while Dr. Bogey applied 100 nM BurD to the cells for 24 hours
b. Dr. Bogey accidentally contaminated her ankle cells with bleach
c. Professor Scrawll applied 100 nM BurD to the cells for 24 hours, while Dr. Bogey applied 1 nM BurD to the cells for 12 hours
d. Professor Scrawll applied 1 nM BurD to the cells for 24 hours, while Dr. Bogey applied 100 nM BurD to the cells for 24 hours
e. Dr. Bogey applied 100 nM BurD to the cells for 24 hours, while Professor Scrawll applied 1 nM BurD to the cells for 12 hours

Answer 1

Answer:

The correct option is C - Professor Scrawll applied 100 nM BurD to the cells for 24 hours, while Dr. Bogey applied 1 nM BurD to the cells for 12 hours.

Explanation:

The correct option is C - Professor Scrawll applied 100 nM BurD to the cells for 24 hours, while Dr. Bogey applied 1 nM BurD to the cells for 12 hours.

As the exotoxin, BurD is very stable and lyse the ankle cells very quickly, more concentration and more time of action should only lyse the cells. Perhaps Dr.Bogey's ankle cells were not lysed because the concentration she used was only 1nM compared to the 100nM concentration used by Dr. Scrawll, and the time period of incubation was only 12 hours compared to the 24 hours used by Dr. Scrawll.

Considering the other explanations given in the remaining options, the concentration and time of incubation used by Dr. Bogey are more than that used by Dr. Scrawll which should only have possibly lysed the cells. Moreover, contamination with bleach also should have only lysed the cells.