you are: GENETICS of MAN'S BARRENESS

Data about influence of factors of environment on health were considered several years ago as the doubtful. At present, alas, it is proved, that as try to avoid influence of bad ecology - the harm all the same brings it. Moreover, it is recognised, that in megacities with bad ecology frequency of congenital infringements of man's sexual system is raised.

Likely, the strongest break in comprehension of man's barreness last 10 years has been made in the field of genetics. Already clearly, that many illnesses which were considered got, actually have a genetic basis. Than the sex of future child is defined? What combination of the basic sexual chromosomes will develop - XX (girl) or XY (boy). When the boy grows, it Y the chromosome becomes responsible for development of man's sexual cages and at changes in this so necessary chromosome can happen so, that spermatozoidy will be "patients" or them will be very little, and even will not appear at all.

If to put end under all above told all problems arising at men can be divided on two huge groups - development infringements spermatozoidov and difficulties with their allocation.