TLS Online TPP Program

#Question id: 2075


The force driving simple diffusion is:

#I Life Science/ Life Sciences Group – I-V
  1. ATP hydrolysis

  2. a concentration gradient

  3. transmembrane pumps

  4. phosphorylated carrier proteins

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TLS Online TPP Program

#Question id: 12948

#SCPH28 | Zoology

Proteolytic cleavage of DNA polymerase by subtilisin caused loss of its nick translation activity. Which of the following properties is lost?

TLS Online TPP Program

#Question id: 12956

#SCPH06 I Botany

For  nearly 200  years, biogeographers have  noted that  the  tropics  have  more terrestrial species than  temperate regions. Which of the following is NOT a plausible explanation for this pattern?

TLS Online TPP Program

#Question id: 12957

#SCPH06 I Botany

Dichlorodiphenyltrichloroethane is related to the phenomenon of:

TLS Online TPP Program

#Question id: 12958

#SCPH06 I Botany

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.

The strong dependence of RR individuals on large quantities of vitamin K probably is responsible for

TLS Online TPP Program

#Question id: 12959

#SCPH06 I Botany

Ozone layer depletion, since the 1970s, is primarily

TLS Online TPP Program

#Question id: 12960

#SCPH06 I Botany

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?