The answer is The Doppler Effect. It is named after the Austrian physicist Christian Doppler, who described the phenomenon in 1842.
Chromosomes condense before<span> mitosis to allow them the ability to move smoothly, without becoming entangled and breaking. (So, </span>they<span> are conveniently packaged for cell division, in which the </span>chromosomes<span> must move to both poles of the cell.) Because when </span>they<span> are un condensed- in chromatin form, </span>they<span>'re unwound.</span>
Option C. the larger A pairs with the smaller T, and the larger G pairs with the smaller C.