Practice Questions

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?

#Unit 10. Ecological Principles

It is a wild-type gene induced to mutate by the direct action of warfarin.
It is a mutation subsequently favoured by natural selection.
It is increased in frequency by virtue of its dominant status.
It is carried by a bacterial plasmid vector.

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TLS Online TPP Program

#Question id: 3764

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TLS Online TPP Program

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TLS Online TPP Program

#Question id: 19462

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TLS Online TPP Program

#Question id: 12134

#Unit 10. Ecological Principles

Which of the following is an example of Müllerian mimicry?

TLS Online TPP Program

#Question id: 3825

#Unit 3. Fundamental Processes

Telomeres are the repetitive sequence of T's and G's that are present in the eukaryotes to protect the random cleavage from nucleases. These telomeres are synthesized by the enzyme telomerase. Which of the following are the properties of enzyme telomerase?