TLS Online TPP Program

#Question id: 12960


The Norway rat (Rattus Norvegicus), a widespread pest, was controlled for about a decade by the anticoagulant warfarin. This chemical substance, placed in food pellets, is absorbed by the intestinal tract and inhibits the clotting of blood. After a population decline for about 10 years, rat populations increased and stabilized. In one European population, as illustrated in the graph below, the percentage of rats resistant to warfarin has remained fairly stable over a number of years.

Resistance to warfarin is governed by a dominant autosomal gene, R. More than 15 percent of the resistant animals are heterozygous at this locus (Rr). The table below indicates the response to warfarin and relative reproductive fitness of individuals that are homozygous or heterozygous for the dominant gene (R). The RR individuals have a 20-fold increase in vitamin K requirement over individuals.

Fitness is a measure of the reproductive success of a particular genotype. The highest fitness is 1.00.
Which of the following is most likely correct concerning the gene for resistance to warfarin? 

#Part-B Specialized Branches in Biotechnology
  1. It is a wild-type gene induced to mutate by the direct action of warfarin.
  2. It is a mutation subsequently favoured by natural selection. 
  3. It is increased in frequency by virtue of its dominant status.
  4. It is carried by a bacterial plasmid vector.
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TLS Online TPP Program

#Question id: 402

#Part-A Aptitude & General Biotechnology

If the DG'° of the reaction A -> B is –40 kJ/mol, under standard conditions the reaction:

TLS Online TPP Program

#Question id: 404

#Part-B Specialized Branches in Biotechnology

When a mixture of 3-phosphoglycerate and 2-phosphoglycerate is incubated at 25 °C with phosphoglycerate mutase until equilibrium is reached, the final mixture contains six times as much 2-phosphoglycerate as 3-phosphoglycerate.  Which one of the following statements is most nearly correct, when applied to the reaction as written?  (R = 8.315 J/mol·K; T = 298 K)  3-Phosphoglycerate -> 2-phosphoglycerate

TLS Online TPP Program

#Question id: 405

#Part-B Specialized Branches in Biotechnology

When a mixture of glucose 6-phosphate and fructose 6-phosphate is incubated with the enzyme phosphohexose isomerase (which catalyzes the interconversion of these two compounds) until equilibrium is reached, the final mixture contains twice as much glucose 6-phosphate as fructose 6-phosphate.  Which one of the following statements is best applied to this reaction outlined below? (R = 8.315 J/mol·K; T = 298 K) Glucose 6-phosphate -> fructose 6-phosphate

TLS Online TPP Program

#Question id: 406

#Part-B Specialized Branches in Biotechnology

Hydrolysis of 1 M glucose 6-phosphate catalyzed by glucose 6-phosphatase is 99% complete at equilibrium (i.e., only 1% of the substrate remains). Which of the following statements is most nearly correct? (R = 8.315 J/mol·K; T = 298 K)

TLS Online TPP Program

#Question id: 407

#Part-B Specialized Branches in Biotechnology

The reaction A + B -> C has a DG'° of –20 kJ/mol at 25° C.  Starting under standard conditions, one can predict that:

TLS Online TPP Program

#Question id: 409

#Part-B Specialized Branches in Biotechnology

For the following reaction,DG'° = +29.7 kJ/mol. L-Malate + NAD+ -> oxaloacetate + NADH + H+ The reaction as written: