Related substances (GC) (Sum of peaks with a relative retention less than that of benzyl alcohol) â¤ 0.02 %: Related substances (GC) (Sum of peaks with a relative retention greater than that of benzyl alcohol) â¤ 0.20 %: Related substances (GC) (disregard limit) â¤ 0.0001 %: Benzene (GC) â¤ 0.0002 %: Chlorobenzene (GC) â¤ 0.01 %: Toluene (GC)
If you're carrying more than one baby, chances are good you'll deliver early. Twins are usually born around 36 weeks -- four weeks early. Triplets arrive at about 33 weeks, and quads often make their debut at 31 weeks.
The main difference between monozygotic and dizygotic twins is that monozygotic twins originate from a single zygote â or fertilized egg â and dizygotic twins come from two zygotes. Monozygotic twins are also called identical twins or maternal twins, and dizygotic twins are also called fraternal twins.Another difference between monozygotic and dizygotic twins is how common they are; about 30 percent of twins are monozygotic, and the other 70 percent are dizygotic.nother difference between monozygotic twins and dizygotic twins is that only monozygotic twins can be conjoined, which means that some parts of their bodies are joined or shared. Many scientists believe that this occurs when the original zygote begins to separate after more than 12 days and is unable to fully divide.