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#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? 

#SCPH06 I Botany
  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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#Question id: 5522

#SCPH28 | Zoology

In reptiles, birds, and mammals, mesoderm is made by invagination and involution into the
TLS Online TPP Program

#Question id: 11376

#SCPH28 | Zoology

Robert MacArthur and E. O. Wilson developed a general model of island biogeography, In this figure, terms A, B, C and D in order are

 
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#Question id: 2715

#SCPH05 I Biotechnology

The interaction between the positively charged amino terminus of histone __________ and a negatively charged region of the histone fold domain of histone __________ is particularly important for 30 nm fibre formation.
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#Question id: 657

#SCPH01 Biochemistry

Structural proteins that typically assemble into large cables or threads to provide mechanical support to cells or organisms are classified as ________ proteins.
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#Question id: 7701

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

The various taxonomic levels (for example, phyla, genera, classes) of the hierarchical classification system differ from each other on the basis of ________