Why does only one egg, rather than four eggs, develop during oogenesis, given that spermatogenesis results in four sperm formed from one stem cell? why does only one egg, rather than four eggs, develop during oogenesis, given that spermatogenesis results in four sperm formed from one stem cell? once formed, spermatids, but not oocytes, undergo additional rounds of division by mitosis. unequal cytoplasmic division ensures that a fertilized egg has ample nutrients for its journey to the uterus. the egg does not go through the meiotic division processes that the sperm undergo. only one egg can be fertilized at a time.

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.