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TLS Online TPP Program

#Question id: 15618

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  isolate  a second Lac– mutation, which you designate lac2-. Using P1 phage on this strain and use the resulting phage lysate to infect the lac2- strain, selecting for   Kanr   transductants. In this case, all 100   Kanr   transductants that are examined are Lac–. What does this result tell you about the relationship between the lac1- and lac2- mutations?

#SCPH01 Biochemistry
  1. lac1- and lac2- mutations are very far from each other, they are linked, and are mutations in two different genes.
  2.  lac1- and lac2- mutations are very far from each other, they are unlinked, and are mutations in same genes.
  3. lac1- and lac2- mutations are linked, and are mutations in same genes.
  4.  lac1- and lac2- mutations are very far from each other, they are unlinked, and are mutations in two different genes.
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TLS Online TPP Program

#Question id: 13063

#SCPH05 I Biotechnology

Precision will be reduced, but yield will be increased
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 statement is worng? Aminopetrin………s
TLS Online TPP Program

#Question id: 5086

#SCPH01 Biochemistry

Cells move to new positions as an embryo establishes its three germ tissue layers during ________.
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#Question id: 5439

#SCPH06 I Botany

Which of the following phenotypes is an example of polygenic inheritance?
TLS Online TPP Program

#Question id: 352

#I Life Science/ Life Sciences Group – I-V

One mole (mol) of glucose (molecular mass = 180 daltons) is ________.
TLS Online TPP Program

#Question id: 4311

#SCPH05 I Biotechnology

At the beginning of this century, there was a general announcement regarding the sequencing of the human genome and the genomes of many other multicellular eukaryotes. Many people were surprised that the number of protein-coding sequences was much smaller than they had expected. Which of the following types of DNA make up the rest of the human genome?