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
More Questions
TLS Online TPP Program

#Question id: 865

#Unit 1. Molecules and their Interaction Relevant to Biology

In autophagy, the endoplasmic reticulum (ER) first gives rise to a cup-shaped, membranous cisterna called the______

TLS Online TPP Program

#Question id: 864

#Unit 1. Molecules and their Interaction Relevant to Biology

Which one is not the appropriate function of Heat Shock Proteins;

TLS Online TPP Program

#Question id: 862

#Unit 1. Molecules and their Interaction Relevant to Biology

Match the following

lysosomal protein degradation pathways

         Found in

1. Nonselective

a-well-nourished cells

i-containing the pentapeptide Lys-Phe-Glu-Arg-Gln

2- Selective

b-starving cells

TLS Online TPP Program

#Question id: 861

#Unit 1. Molecules and their Interaction Relevant to Biology

Alexander Varshavsky discovered, the half-lives of many cytoplasmic proteins vary with the identities of their N-terminal residues via the so-called N-end rule:-

A. Destabilizing N-terminal residues Asp, Arg, Leu, Lys, and Phe have half-lives of

i. Only 2 to 3 minutes,

B. Stabilizing N-terminal residues Ala, Gly, Met, Ser, Thr, and Val have half-lives of

ii. >10 hours in prokaryotes

iii. >20 hours in eukaryotes.

TLS Online TPP Program

#Question id: 860

#Unit 1. Molecules and their Interaction Relevant to Biology

Select true ‘T’ AND false ‘F’ about ubiquitinylation

I. These ubiquitin-like modifiers control processes as diverse as nuclear import,

II. Regulated by the ubiquitin-like modifier Sumo, and autophagy,

III. Regulated by the ubiquitin-like modifier Atg8.

IV. For a protein to be efficiently degraded, it must be linked to a chain of at least four tandemly linked ubiquitin molecules in which Lys 34 of each ubiquitin forms an isopeptide bond with the C-terminal carboxyl group of the following ubiquitin.

TLS Online TPP Program

#Question id: 654

#Unit 1. Molecules and their Interaction Relevant to Biology

Which pair represents different conformations?