Table 201
the Following Data Were Obtained from a Broth Dilution

question 36

Multiple Choice

Table 20.1
The following data were obtained from a broth dilution test. $\begin{array}{c}&&\text { Growth in }\\\text { Concentration of Antibiotic } X&\text { Growth }&\text { Subculture }\\\hline2 \mu \mathrm{g} / \mathrm{ml} &+&+\\10 \mu \mathrm{g} / \mathrm{ml}&-&+ \\15 \mu \mathrm{g} / \mathrm{ml} &-&-\\25 \mu \mathrm{g} / \mathrm{ml}&-&-\end{array}$
-In Table 20.1, the minimal inhibitory concentration of antibiotic X is

• A) 15 µg/ml.
• B) 2 µg/ml.
• C) 25 µg/ml.
• D) 10 µg/ml.
• E) Can't tell.

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Definitions:

Operon

A functioning unit of DNA containing a cluster of genes under the control of a single promoter, found in prokaryotes and some viruses.

Repressible Genes

Genes whose expression can be decreased or halted in response to specific stimuli or conditions, as part of cellular regulatory mechanisms.

Transcribed

The process in which a segment of DNA is copied into RNA by the enzyme RNA polymerase.

End Product

The final product resulting from a process, often after a series of intermediate stages or chemical reactions.