You will be given a definition of a task first, then some input of the task.
In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

structures resolve a problem first recognized by Alexei Olovnikov, although they are not necessary in most bacteriophages and bacteria. Their namesake enzyme was first discovered in Tetrahymena. That enzyme is a ribonucleoprotein which carries out reverse transcription to add several repeats of a six-nucleotide sequence, (*) TTAGGG. Hydrogen bonding between those guanine residues creates a hairpin structure, which enables the rest of the lagging strand to be filled in. Although they are extremely stable in most tumor cells, these structures gradually shorten as a normal somatic cell ages. For 10 points, name these segments of DNA which protect the ends of linear chromosomes from decay.
Output:
Science