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.
The test could conceivably help parents who are worried about gender-related diseases, but it could also allow people to wade into the morally murky waters of sex selection. The test analyzes fetal DNA found in a mother's blood, according to a report in the New York Times. If a Y chromosome is present, the mother is having a boy; if it's not, it probably means the fetus is female (but could also mean that blood sample doesn't contain fetal DNA). Researchers examined 57 studies of fetal DNA tests, spanning some 6,500 pregnancies.