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#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: 10333

#Unit 6. System Physiology – Plant

Four elements, oxygen, carbon, and hydrogen and nitrogen are the major components of most organic compounds, which of the following elements are more abundant in plants ?
TLS Online TPP Program

#Question id: 13194

#Unit 1. Molecules and their Interaction Relevant to Biology

If we have the sequence 5’-ATGTC-3’ on one chain, the opposite chain must have the complementary sequence 
TLS Online TPP Program

#Question id: 756

#Unit 1. Molecules and their Interaction Relevant to Biology

The thermal denaturation of DNA may be reversed by cooling the solution. Rapid cooling allows:
TLS Online TPP Program

#Question id: 1244

#Unit 4. Cell Communication and Cell Signaling

Which type of experimental evidence shows that the intrinsic GTPase activity of the Gα subunit is important for terminating effector activation?
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#Question id: 12720

#Unit 6. System Physiology – Plant

Several genes coding for enzymes associated with osmotic adjustment are turned on (up-regulated) by osmotic stress and/or salinity, and cold stress. These genes encode enzymes such as the following;
I) ∆′1-Pyrroline-5-carboxylate synthase, a key enzyme in the proline biosynthetic pathway
II) myo-Inositol 6-O-methyltransferase, a rate-limiting enzyme in the accumulation of the cyclic sugar alcohol called pinitol
III) Betaine aldehyde dehydrogenase, an enzyme involved in glycine betaine accumulation
Given following statements of gene encoding enzyme is correct?