It is important to distinguish the 5' and 3' UTRs from other non-protein-coding RNA. Within the coding sequence there can be found sections of RNA that will not be included in the protein product. These sections of RNA are called introns. The RNA that results from RNA splicing are called exons. The reason why introns are not considered untranslated regions is that the introns are spliced out in the process of RNA splicing. The introns are not included in the mature mRNA molecule.

Is it true that is 5' utr present in mature mrna?
yes