TLS Online TPP Program

#Question id: 13143


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.
In a population where warfarin is no longer applied, the expectation is that the

#Unit 10. Ecological Principles
  1. Dominant gene (R) will supplant the recessive gene (r) in the population
  2. Heterozygotes (Rr) will have a reproductive advantage over both homozygotes (RR and rr) 
  3. Frequency of the dominant gene (R) will decline
  4. Frequency of recessive individuals will gradually decline
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TLS Online TPP Program

#Question id: 464

#Unit 1. Molecules and their Interaction Relevant to Biology

Calculate the equilibrium constant for an oxidation-reduction reaction involving the transfer of 1 mole of electrons with DE0สน= 0.25 V. (R = 8.315 JK-1mol-1, F = 96.48 kJV-1mol-1, T = 298 K)

TLS Online TPP Program

#Question id: 465

#Unit 1. Molecules and their Interaction Relevant to Biology

If the standard reduction potential of a certain half-reaction is -0.30 V, which statement below is true for this half-reaction to proceed as a reduction?

TLS Online TPP Program

#Question id: 466

#Unit 1. Molecules and their Interaction Relevant to Biology

When a reduction half-reaction is ________ (negative, positive), electrons flow to the more readily reduced substance which is ________ (negative, positive) in value.

TLS Online TPP Program

#Question id: 467

#Unit 1. Molecules and their Interaction Relevant to Biology

The standard potential for electron transfer can be related to the standard free-energy change for redox reactions by using

TLS Online TPP Program

#Question id: 468

#Unit 1. Molecules and their Interaction Relevant to Biology

Glycolysis is the name given to a metabolic pathway occurring in many different cell types.  It consists of 11 enzymatic steps that convert glucose to lactic acid.  Glycolysis is an example of

TLS Online TPP Program

#Question id: 469

#Unit 1. Molecules and their Interaction Relevant to Biology

The anaerobic conversion of 1 mol of glucose to 2 mol of lactate by fermentation is accompanied by a net gain of: