f£ <‘- f > y. 6 „•; 
-r 
Figure 5: Embryo after cleavage, [www.visembryo.com by Mouseworks, Inc.) 
I Cag^CBplioit Isi tti^ i 
I E 
i Iri S/itm FmtiUzatItm {IVWjt llfetally j 
I ^’lertiliaatloa in glass'^ Is Ife procedwa 1 
j df ccmbining eggs and eperm ontsid# j 
i the tedy in a disb. The aygotss that am | 
I the restilts of snceassful conception, if | 
I any, aia grown in cnlttiie for a few days | 
j and . then transferred to the ntems of the j 
i mother. It may be used when the [ 
I prospective mother' has damaged 
uterme tubes. Lomae Brown, the first | 
baby from IVf was bom July 25, 1978, | 
in the UK. IVP was put into practice in , 
the US. starting in 1981 and there Itave 
since been over 114,000 U.S. IVF births. 
j Intracytoplasmic Sperm Injection (IGSI) 
is a variation on IVF. Instead of |ust 
allowing sperm and eggs to come into 
contact in a dish, a technician 
physically pfeces a sperm cell inside 
the egg ceh through the egg membrane. 
IGSI is used, among other reasons, 
when the prospective father has some 
concMtion affecting fertility^ stich as a 
low sperm count. 
Usually more eggs are collected for 
fertilization than would be transferred 
at one time, both to increase likelihood 
of some successful conceptions, and 
because the process of collecting eggs 
involves hormonal treatments that can 
be uncomfortable and risky for the 
woman. Any early embryos that are not 
transferred right away are usually 
stored frozen for later transfer. But 
many of these are not transferred. In 
the U.S. as of June 2002 there were 
approidniately 400,000 embryos in 
storage. 
syngamy. In this integration, the 
diploid chromosome number is 
restored, and a new complete 
genome comes into being. The result 
of syngamy is an entity with an 
individual genome. Further, if all 
goes well, it is an entity that is 
capable of developing into a fully 
formed individual of the species. The 
fertilized egg is now called a zygote. 
It is at this point already entering the 
first stage of its first mitotic division, 
and beginning cleavage (Figure 5). 
Figure 4F: Fertilization, Syngamy 
Like other vertebrates, humans have polarity in three dimensions 
(head-tail, or back-front, and left-right). Establishing polarity is one of 
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