Practice Questions

  1. Home
  2. Free Resources
  3. Practice Questions
  4. 2879
TLS Online TPP Program

#Question id: 2904

When the temperature of a solution of DNA is raised to near the boiling point of water, the optical density, (called absorbance) at 260 nm markedly increases, a phenomenon known as hyperchromicity. Which of the following properties gets changed due to subsequent denaturation of the DNA molecule?

#Unit 2. Cellular Organization

  1. The solutions of native DNA exhibit high viscosity because of the relatively rigid double helical, long and rod like character of DNA molecule. Denaturation causes a marked decrease in viscosity.

  2. Denaturation of DNA double helix can also be brought about by certain chemical agents such as urea and formamide. These chemical reagents enhance the aqueous solubility of the purine and pyrimidine groups.

  3. Double-stranded DNA shows a strong positive rotation which highly decreases with denaturation. This change is analogous to the change in rotation observed when the proteins are denatured.

  4. All of the above

More Questions
TLS Online TPP Program

#Question id: 7589

#General Aptitude

A train of length 500 m crosses a platform of length 50% more than the length of the train in 50 seconds. Find the time taken by this train to cross another train of same length running with double the speed of first train in the opposite direction.
TLS Online TPP Program

#Question id: 7590

#General Aptitude

The ratio of the length of two trains X and Y is 4 : 7 and the ratio of the time taken by both trains to cross a man standing on a platform is 2 : 3. If the speed of the train y m/sec
TLS Online TPP Program

#Question id: 7591

#General Aptitude

A pilot flies an aircraft at a certain speed for a distance of 800 km. He could have saved 40 min by increasing the average speed of the plane by 40 km/h. Find the average speed of the aircraft.
TLS Online TPP Program

#Question id: 7592

#General Aptitude

A train started from point A at a speed of 60 km/hr and after 2 hours another train of same length started from A at a speed of 80 km/hr in the same direction as the first one. After how much time the second train will meet the first train?
TLS Online TPP Program

#Question id: 7593

#General Aptitude

An aeroplane files along the four sides of a square at the speeds of 200 , 400 , 600 and 800 km/hr. Find the average speed of the plane around the field
TLS Online TPP Program

#Question id: 7594

#General Aptitude

A car travels the first one third of a certain distance with a speed of 10 km/hr , the next one third distance with a speed of 20 km/hr , and the last one third distance with a speed of 60 km/hr . The average speed of the car for the hole journey is :