Biology GK Questions Quiz-50

981. Thiamidine dimer formation in DNA is caused by (1) IR-rays  (2) X-rays (3) b and g-rays  (4) UV-rays Answer: 981. (4) When cells are exposed to sunlight, radiant energy can damage the DNA. For example, ultraviolet irradiation causes covalent bond formation between adjacent thymines on the same strand of DNA. Ultraviolet light is absorbed by a double bond in thymine and cytosine bases in DNA. This added energy opens up the bond and allows it to react with a neighboring base. 982. Which one of the following statements about PYROLYSIS, which is a process for solid waste treatment is incorrect? (1) It converts the waste into solid, liquid and gas of which the resultant liquid and gas can be used to produce energy. (2) The process occurs at a temperature above 430°C at atmospheric pressure. (3) The process occurs under high pressure at temperature above 430° C. (4) It is a thermochemical decomposition of organic waste Answer: 982. (2) Pyrolysis is a thermo-chemical decomposition of organic material …