Optimisation of a PCR reaction is often a compromise between the competing demands for precision, efficiency and yield. Although the specific effects may vary, generally, increasing the annealing temperature will increase non-specific primer binding and reduce precision. Increasing the length of the elongation phase will reduce the proportion of incomplete newly-synthesised strands and therefore increase yield. In this case, the potential effect on efficiency is unclear. Increasing the elongation phase would increase the reaction time, but the time taken to ramp down to a lower annealing temperature would be reduced.

Which of the following techniques doesn’t involve use of a secondary antibody?

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#Question id: 3642

#SCPH06 I Botany

Any piece of DNA which replicates as a single unit is called

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#Question id: 3890

#SCPH05 I Biotechnology

Small signal molecules that regulate transcription are not known to:

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#Question id: 15620

#SCPH28 | Zoology

Wild type E. coli metabolizes the sugar lactose by expressing the enzyme ß-galactosidase. You have isolated a mutant that you call lac1–, which cannot synthesize ß-galactosidase and cannot grow on lactose (Lac–). During an condition Lac– strain, called lac3–, is linked to the Tn5 insertion. From a strain carrying the Tn5 insertion and lac3– mutation you isolate an F’ that caries a region of the chromosome that includes both Tn5 and the linked Lac region. Introduce this F’ into an F– strain carrying lac1– by selecting for Kanr. These merodiploids express ß-galactosidase normally. What does this result tell you about the relationship between the lac3– and lac1- mutations?  

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#Question id: 15879

#SCPH05 I Biotechnology

During which Phase lasts about 3-4 cell generations (the time taken for doubling of cell number), and the duration of a cell generation may vary from 22-48 hr, depending mainly on the plant species?

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#Question id: 3676

#SCPH28 | Zoology

Which function can be carried out by DNA replication proteins?