In the Chinese calendar, the days begin at midnight and end at the next midnight, but people tend to regard the days as beginning at dawn. Currently, the time in days are scaled with hour-minute-second system. In ancient China, the time is divided according to either the shi-shÃ­ ke kÃ¨-and gÄng. diÇn systems
maternal lineage, or 2) Y-chromosome DNA which is inherited through the fatherâs line and is. passed down only to males in each generation and can give information only to males about his. paternal lineage. The other type of genetic ancestry test is one that makes estimates of a personâs ancestry by.
In mammals, the Y chromosome contains the gene SRY, which triggers testis development. The DNA in the human Y chromosome is composed of about 59 million base pairs. The Y chromosome is passed only from father to son. With a 30% difference between humans and chimpanzees, the Y chromosome is one of the fastest-evolving parts of the human genome.