The answer would be the ozone layer. <span>A layer of ozone in the upper atmosphere absorbs </span>UV radiation<span> and </span>prevents<span> most of it from </span>reaching<span> the </span>Earth<span>. ... This means that more </span>ultraviolet radiation<span> can pass through the atmosphere to the </span>Earth's<span> surface, particularly at the poles and nearby regions during </span>certain<span> times of the year.
Gametes are produced by meiosis, the cell division that reduces the chromosome number to Half.
The Gametes need to be Haploid so that the Chromosome number of the species is maintained. Otherwise the Chromosome number would have doubled in each progeny.
Thus, clearly we can conclude that the eggs and sperms of raptors have three chromosomes each.
