Answer:
The correct option is <em>B) ultraviolet region, especially below a wavelength of 320 nm.</em>
Explanation:
Ultraviolet light carries an enormous amount of energy in it. It is invisible to the human eye. When UV light with enormous energy and wavelength lesser than 320nm, hits the DNA, it causes changes in the structure of the DNA. Mostly, it affects the thymine nitrogenous base regions and forms pyrimidine dimers. The structure of the DNA changes on all the sites where dimers form and hence, they cannot be properly transcribed.
Answer:
Meiosis occurs in a series of different phases and creates genetically unique reproductive cells. The process which helps make meiotic cells genetically different and occurs during prophase I, but not during prophase II, is crossing over (C). Crossing over is the exchange of genetic material between two homogenous chromosomes. It is one of the final phases of prophase I. This process is called synapsis. It occurs when the matching regions on the matching chromosomes break and then reconnect to the other chromosome
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