Crossing over is a process that happens between homologous chromosomes in order to increase genetic diversity. During crossing over, part of one chromosome is exchanged with another. The result is a hybrid chromosome with a unique pattern of genetic material.
Hmmm i think its the third one because men only have 1 x chromosome therefore without the other one if the x chromosome on a men carries a disorder it will show because there is no other chromosome to balance it out and in women the disorder has to show on both X chronosome (and its rarer) for a disorder to appear therefore women having a second X chromosome is effectively a protection
I think at Approximately 7 years the child should be able to use each hand independently. Hand control is the ability by a child to accurately use and manipulate objects, utensils, tools and even finger in isolation for functional tsak performance.
<span>I would say Convergent evolution. </span>