What is the minimum number of immunoglobin molecules possible if there are 3,000 variants possible for the light chain and 5,000 variants possible for the heavy chain?
What will be an ideal response?
Which of the following is not a way in which RecA activity is regulated?
A. transcription of the RecA gene
B. autoregulation
C. regulation by binding of other proteins
D. regulation by other proteins that block RecA binding; for example, single-strand binding proteins (SSB)
E. translation of the RecA protein
Which of the following characteristics of the lactose operon is not true of the galactose operon?
A. Repressor binding prevents RNA polymerase from binding to the promoter.
B. CRP activates expression when bound to cAMP.
C. Expression is high when glucose levels are low and the activating metabolite is present.
D. Expression is low when glucose levels are high.
When complexing with histones, the DNA phosphodiester backbone is in close proximity to:
A. the histone fold, two helices connected by two short links, this motif being found within H1, H2A, H2B, H3, and H4
B. the histone fold, two helices connected by two short links, this motif being found within H2A, H2B, H3, and H4
C. the histone fold, three helices connected by two short links, this motif being found within H1, H2A, H2B, H3, and H4
D. the histone fold, three helices connected by two short links, this motif being found within H2A, H2B, H3, and H4
What helical forms are adopted by double-stranded RNA?
A. There is evidence for B-form RNA in viruses.
B. There is no evidence that A-form RNA occurs in cells.
C. The A form is the only form found for double-stranded RNA in cells and in viruses.
D. There is evidence that Z-form RNA occurs in cells under certain conditions.
E. The A form occurs only in the laboratory.
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