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TLS Online TPP Program

#Question id: 2884

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 statement is INCORRECT from the given set of statements?

#Unit 2. Cellular Organization

  1. The explanation for this increase is that duplex DNA absorbs more ultraviolet light by ~40% than do individual DNA chains.

  2. This hyperchromicity is due to base stacking, which increases the capacity of the bases in duplex DNA to absorb ultraviolet light.

  3. The sharpness of the increase in absorbance at the melting temperature tells us that the denaturation and renaturation of complementary DNA strands is a highly cooperative, zippering-like process.

  4. At high ionic strength, the negative charges are shielded by cations, thereby destabilizing the helix. Conversely, at low ionic strength, the unshielded negative charges render the helix more stable.

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TLS Online TPP Program

#Question id: 7501

#General Aptitude

A train 150 m long is running with a speed of 68 kmph. In what time will it pass a man who Is running at 8 kmph in the same direction in which the train is going?
TLS Online TPP Program

#Question id: 7502

#General Aptitude

A train 220 m long is running with a speed of 59 kmph. In what time will it pass a man who is running at 7 kmph in the direction opposite to that in which the train is going?
TLS Online TPP Program

#Question id: 7503

#General Aptitude

Two trains 137 metres and 163 metres in length are running towards each other on parallel lines,one at the rate of 42 kmph and another at 48 kmph. In what time will they be clear of each other from the moment they meet?
TLS Online TPP Program

#Question id: 7504

#General Aptitude

Two train 100 metres and 120 metres long are running in the same direction with speed of 72 km/hr and 54 km/hr. In how much time will the first train cross the second?
TLS Online TPP Program

#Question id: 7505

#General Aptitude

A train running at 54 kmph takes 20 seconds to pass a platform .Next it takes 12 seconds to Pass a man walking at 6 kmph in the same direction in which the train is going. Find the length of the train and the length of the platform.
TLS Online TPP Program

#Question id: 7506

#General Aptitude

A man sitting in a train which is travelling at 50 kmph observes that a goods train,travelling In opposite direction,takes 9 seconds to paas him. If the goods train is 280 m long,Find its speed.