To confirm whether bones belong to the Romanov children, a relative of the Tsarina would be more useful because the Tsarina's matrilineal DNA lineage (mitochondrial DNA) is less common and more distinct than the Tsar's, making it easier to identify a direct genetic match.

Yes, to confirm whether bones belong to the Romanov children, using a relative of the Tsarina would indeed be useful, particularly because of the properties of mitochondrial DNA (mtDNA). mtDNA is passed down from a mother to her children without recombination, which means both sons and daughters get it unchanged from their mother. Since Tsarina Alexandra was a member of a distinct European royal lineage, her mtDNA haplotype (a group of genes inherited together from a single parent) would be more unique and less common. The Tsar's Y-chromosome DNA, on the other hand, would be less useful for identifying the remains of his children, especially his daughters, because Y-chromosome DNA is only passed from father to son.

The identification process consists of extracting mtDNA from the remains and comparing them to the mtDNA of known living relatives (in this case, those related to the Tsarina). If the mtDNA sequences match, this can provide a strong indication that the bones belong to the Romanov children. It's a powerful tool in forensic science for establishing maternal lineage.

Extra: Understanding DNA is crucial in this context. DNA, or deoxyribonucleic acid, contains the genetic instructions for the development and function of living things. There are two types of DNA used in genetic ancestry and forensic investigations:

1. Nuclear DNA: This is the DNA located within the nucleus of a cell and it contains information from both parents. Because it's a mix, it can be more difficult to trace a direct ancestor, especially with generations of intermixing.

2. Mitochondrial DNA (mtDNA): This type of DNA is found in the mitochondria, which are like little powerhouses of the cell. Unlike nuclear DNA, mtDNA is passed down from mother to offspring without any genetic material from the father. This makes mtDNA a powerful tool for tracing maternal lineage, as it stays relatively unchanged through generations.

Mitochondrial DNA played a critical role in the identification of the remains of the Romanov family, the last royal family of Russia, who were executed in 1918 following the Russian Revolution. Because the Tsarina's mtDNA had fewer opportunities to mix with the broader population compared to the Tsar's lineage, geneticists and forensic experts believe that her mtDNA presents a more direct genetic link to her offspring. This reasoning was used during the investigation of the Romanov remains in the 1990s, and with the help of genetic analysis and comparison with living relatives on the Tsarina's maternal side, it helped to corroborate the identities of the Romanov children.