You are studying a new strain of E. coli that can utilize the disaccharide melibiose very efficiently. You find that utilization depends on the enzyme melibiase, which is encoded by the gene Mel1. Mel1 is not expressed unless melibiose is present in the growth medium.

Next, you isolate a third mutant, MelC–, which gives constitutive melibiase expression. The MelC– mutation is closely linked to Mel1 and MelB–. Genetic tests of the MelC– mutation yield the following:

 

As above, classify the MelC– mutation in terms of its basic genetic properties and explain how you arrived at your conclusions.

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#Question id: 11500

#Unit 9. Diversity of Life Forms

The strongest evidence for the endosymbiotic origin of eukaryotic organelles is the similarity between extant prokaryotes and which of the following?

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#Question id: 2901

#Unit 2. Cellular Organization

HOTAIR is a lncRNA whose gene is found in the HoxC cluster in humans, but it acts by regulating expression of the HoxD genes on another chromosome (in trans) by recruiting to that locus Polycomb Repressive Complex 2 (PCR2). Which of the following processes is incorrect regarding this regulation?

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#Question id: 26503

#Unit 3. Fundamental Processes

Match the following

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#Question id: 4478

#Unit 3. Fundamental Processes

In prokaryotes during abortive initiation, the polymerase synthesizes a series of short transcripts. In eukaryotes, promoter escape involves;

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#Question id: 17821

#Unit 13. Methods in Biology

is most frequently observed data value