It has been observed that when the sugar source changes in a growth medium, the growth rate of yeast vary widely in response. Some strains of yeast are slow to induce catabolic operons while other strains quickly synthesize proteins to process the new sugar. What might be one explanation for this difference in the growth rate of the strains?
A. Operons for anabolic pathways are controlled by many global regulatory mechanisms, and different sugars can favor initiation of different pathways depending on the strain of yeast.
B. Different sugars can act as effector or repressor molecules in various strains, promoting or inhibiting transcription of genes depending on the type of sugar present.
C. Catabolic repression strategies of operons for using different sugars may vary among strains, thereby favoring initiation of transcription in one strain over another depending on the sugar.
D. All of the choices are correct.
Answer: C
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