The Y chromosome sequence remained a mystery as its DNA sequences are filled with long repetitive sequences called satellite DNA, and palindromes, both of which make it difficult to get an accurate reading of the DNA sequence.| ScienceABC
Atoms themselves do not "measure" time in a way that we typically think of. But they play a major role as the basis for highly accurate and precise time measurements. An atomic clock uses atomic vibrations to measure time intervals.| ScienceABC