介绍： 版权归原作所有，仅供此学习，若有侵权请告知删除。
[12:17.90]The last reading.
[12:20.14]DNA Testing
[12:22.58]DNA testing is a powerful tool for identification
[12:26.65]and has many practical applications.
[12:30.18]Molecule DNA carries our genetic code
[12:33.34]and determines our characteristics.
[12:36.29]...

介绍： 版权归原作所有，仅供此学习，若有侵权请告知删除。
[12:17.90]The last reading.
[12:20.14]DNA Testing
[12:22.58]DNA testing is a powerful tool for identification
[12:26.65]and has many practical applications.
[12:30.18]Molecule DNA carries our genetic code
[12:33.34]and determines our characteristics.
[12:36.29]99.9% of the DNA from two people will be identical.
[12:42.25]The 0.1% of DNA code sequences that vary individually
[12:47.11]are called genetic markers.
[12:50.35]The key to DNA testing is to find the genetic markers
[12:54.54]that will identify the important similarities or differences between people.
[13:00.44]The accuracy of DNA tests has big implications.
[13:05.39]They are sometimes the only evidence to prove a suspect was guilty,
[13:09.75]or free someone wrongly convicted.
[13:13.58]It's easy to tell if DNA from two biological samples doesn't match.
[13:19.01]But a match doesn't ensure
[13:20.89]that the two samples come from the same person.
[13:24.37]A small chance exists
[13:26.26]that two different people's genetic markers could be the same,
[13:30.74]especially if they are related.
[13:33.31]However, the chance that two unrelated people have identical profiles
[13:38.40]is less than one in one billion.