Why are introns removed from mRNA?
Most eukaryotic genes and their pre-mRNA transcripts contain noncoding stretches of nucleotides or regions that are not meant to be made into protein. These noncoding segments are called intronsand must be removed before the mature mRNA can be transported to the cytoplasm and translated into protein.If introns are not removed, the RNA would be translated into a nonfunctional protein.
Introns are the non-coding part of the mRNA ,it is considered as a junk and are not helpful in protein coding
For protein synthesis, mRNA exons(coding ) only needed.So, introns(non-coding) were removed from mRNA.