TLS Online TPP Program

#Question id: 3351


In pre-industrial period in England, most peppered moths had light coloration. During industrial revolution, many lichens died out and trees became blackened by soot from factories and interestingly, dark colored moths were predominantly seen. Which of the following observation is incorrect about above selection?

#Unit 11. Evolution and Behavior
  1. It is a directional or progressive selection

  2. Industrial melanism is an adaptation where the moths living in the industrial areas developed melanin pigment to hide themselves from their predators

  3. This happened due to natural selection of the camouflaging mechanism or the moths.

  4. It reduces the variations and maintains the mean value in a population, thereby preventing the evolutionary change

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TLS Online TPP Program

#Question id: 14969

#Unit 2. Cellular Organization

 A new drug is developed that targets and binds to the lipid A portion of LPS from Gram negative bacterial cells. This drug shows a high degree of activity and binding in a test tube setting against purified lipid A. Based on this information,

TLS Online TPP Program

#Question id: 14970

#Unit 2. Cellular Organization

A research lab is trying to produce new antibiotics. They come up with drugs that detach the hydrophilic heads from the phospholipids in plasma membranes. This drug

TLS Online TPP Program

#Question id: 14971

#Unit 2. Cellular Organization

Bacillus and Clostridium are medically relevant groups of bacteria that characteristically stain 

TLS Online TPP Program

#Question id: 14972

#Unit 2. Cellular Organization

Although O side chains are readily recognized by host antibodies, gram negative bacteria may thwart host defenses by 

TLS Online TPP Program

#Question id: 14976

#Unit 2. Cellular Organization

Plasmids are not required for host growth and reproduction, although they may carry genes that give their bacterial host a selective advantage. Plasmid genes can render  bacteria 
1. Drug-resistant 
2. Give new metabolic abilities 
3. Make them pathogenic

Which among the following combinations is correct?

TLS Online TPP Program

#Question id: 14977

#Unit 2. Cellular Organization

Careful electron microscopic studies often have shown the nucleoids are present in contact. Thus bacterial DNA is attached to