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The trophozoite is the inactive dormant stage of protozoa and the cyst is an act

ID: 170262 • Letter: T

Question

The trophozoite is the inactive dormant stage of protozoa and the cyst is an active feeding stage To make certain that anaerobic conditions exist in a Gaspak anaerobic jar a strip of sodium thioglycollate is placed in the jar. All the media you have used for anaerobic growth contained sodium thioglycollate. Members of the genus Bacillus are anaerobic spore formers. Members of the genus Clostridium are anaerobic spore formers. Many media in microbiology are called defined media because A. the exact composition o individual amino acids, vitamins, growth factors and other components are not exactly known B. the exact composition of the individual amino acids, vitamins, growth factors and other components are exactly known. C. they contain special constituents for the growth of some defined bacteria D. they contain special constituents to support anaerobic growth. which of the following provides the specific temperature requirements for growth of microorganisms? A. Autoclave B. Candle jar C. Incubator D. Incinerator A disinfectant should be used on the laboratory work surface A. before the beginning of laboratory work B. after all work is completed C. after any spill of live microorganisms D. should apply to all the above E. should apply only to A and B above

Explanation / Answer

Answer:

32. False

Trophozoite - metabolically active, motile and reproduce all inside host.
Cyst - metabolically inactive, dormant inside host.

33. True

The envelope contains two chemical elements, sodium borohydride and sodium bicarbonate. Water reacts with these chemicals, in the envelope and produce hydrogen gas and carbon dioxide. The hydrogen gas then combines with available free oxygen in the chamber to produce water, removing all free oxygen from the chamber.

34. False

Sodium thioglycollate is a non selective for cultivation of anaerobes, as well as facultative anaerobes and aerobes. There are several other media such as Bacterioides bile esculin agar, Laked Kanamycin-vancomycin blood agar, etc. used for anaerobic growth.

35. False

Members of Bacillus sp. such as Bacillus sphaericus and Bacillus cereus are aerobic microorganisms.