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: 10650

#Section 2: Evolution

Following some characteristic feature of K selected species

A. semelparity 

B. Mate choice

C. Density independent mortality

D. large size of offspring

What is the above combination is correct?

#Question id: 10651

#Section 2: Evolution

Which of the following value of A, B and C in above logistic growth of hypothetical population respectively?

#Question id: 10652

#Section 2: Evolution

Which factors (limited space or overcrowding; limited food; Predators; parasite and diseased) tend to act in a density-dependent manner; Tony Sinclair (1989) many studies of density dependence in 51 populations of insects, 82 populations of large mammals, and 36 populations of small mammals and birds. Which of the following observation is most likely true?

a) Insects showed a wide variety of causes of density dependence and no one density-dependent factor was of overriding importance

b) The lesser the amount of available food, the greater the mortality of large mammals

c) Space and social interactions were more important for smaller mammals and birds, because they are more territorial

#Question id: 10653

#Section 2: Evolution

All offspring are produced in a single reproductive event, we term this pattern semelparity. Which of the following is characteristics feature for semelparity individuals?

a) Semelparity is common in insects and other invertebrates

b) Semelparous organisms may live for many years before reproducing

c) semelparity occur only in plant

d) In semelparity, exploitation competition is more common than interference competition

#Question id: 10654

#Section 2: Evolution

Complete the following hypothetical life table for a bird

What will be population size in next generation?

#Question id: 10655

#Section 2: Evolution

Which of the following statements about the evolution of life histories is correct?

A) Unstable environments with unlimited resources favor r-selected populations.

B) K-selected populations are most often found in environments where density-independent factors are important regulators of population size.

C) Most populations have both r- and K-selected characteristics that vary under different environmental conditions.

D) The reproductive efforts of r-selected populations are directed at producing just a few offspring with good competitive abilities.