TLS Online TPP Program

#Question id: 13142


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.
There is a substantial number of heterozygotes in the population. Which of the following is the best explanation of this observation?

#Unit 10. Ecological Principles
  1. Heterozygotes (Rr) have a selective advantage over both homozygotes (RR and rr). 
  2. The gene for susceptibility (r) is increasing rapidly each generation.
  3. The gene for susceptibility (r) is being lost by chance each generation.
  4. Dominant homozygotes (RR) enjoy a reproductive advantage over heterozygotes
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TLS Online TPP Program

#Question id: 539

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following mutases catalyze the formation of a 2,3-BPG intermediate?

A) muscle phosphoglycerate mutases

B) plant phosphoglycerate mutases

C) yeast phosphoglycerate mutases

TLS Online TPP Program

#Question id: 538

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following statements are correct about cells that form ATP mainly by glycolysis are

A) anaerobic yeasts.

B) lactic acid bacteria.

C) kidney medulla cells.

TLS Online TPP Program

#Question id: 537

#Unit 1. Molecules and their Interaction Relevant to Biology

Substrate level phosphorylation

A) describes the conversion of ADP into ATP with the addition of inorganic phosphate every place throughout the cell.

B) describes the formation of ADP by phosphoryl group transfer from 1,3 bisphosphoglycerate.

C) is the formation of ATP by phosphoryl group transfer from a higher energy compound.

TLS Online TPP Program

#Question id: 536

#Unit 1. Molecules and their Interaction Relevant to Biology

Glucose 6-phosphate allosterically inhibits

A) hexokinase I.

B) glucokinase.

C) hexokinase II.

TLS Online TPP Program

#Question id: 535

#Unit 1. Molecules and their Interaction Relevant to Biology

In some diabetic patients, glucose increases disproportionately and is unresponsive to an insulin challenge; under these conditions, how would oneʹs liver normally respond?

A) phosphorylating glucose for entry into the glycolytic pathway

B) saturating glucokinase with glucose

C) phosphorylating glucose for entry into the glycogen synthesis pathways

TLS Online TPP Program

#Question id: 534

#Unit 1. Molecules and their Interaction Relevant to Biology

If glucose labeled with 14C in C-3 is metabolized to lactate via fermentation, the lactate will contain 14C in: