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? 

#Question id: 9593

#Unit 6. System Physiology – Plant

The lower-energy orbital of the positively charged oxidized reaction centre chlorophyll has a vacancy and can accept an electron If the acceptor molecule donates its electron back to the reaction centre chlorophyll, What will happened?

#Question id: 9594

#Unit 6. System Physiology – Plant

The first reaction that converts electron energy into chemical energy—What will happened in  the primary photochemical event—

#Question id: 9595

#Unit 6. System Physiology – Plant

The process is that the absorbed photon causes an electron rearrangement in the reaction centre chlorophyll, followed by an electron transfer process in which part of the energy in the photon is captured in the form of

#Question id: 9596

#Unit 6. System Physiology – Plant

The reaction centre chlorophyll is transiently in an oxidized state after losing an electron and before being re-reduced by its electron donor, what characteristics has been shown by chlorophylls in an oxidized state?

#Question id: 9597

#Unit 6. System Physiology – Plant

The reaction centre bacteriochlorophyll from purple photosynthetic bacteria was similarly identified as-

#Question id: 9598

#Unit 6. System Physiology – Plant

In the oxidized state, reaction centre chlorophylls contain an unpaired electron, Molecules with unpaired electrons can often be detected by a magnetic-resonance technique known as