Final answer:
Introns are removed through a process called splicing before protein synthesis. Splicing is conducted by complexes of proteins and RNA molecules called spliceosomes.
Step-by-step explanation:
Eukaryotic genes are composed of protein-coding sequences called exons and intervening sequences called introns. Introns need to be removed before protein synthesis. The process of removing introns and reconnecting exons is called splicing. Splicing occurs through a sequence-specific mechanism that ensures introns are removed and exons rejoined with accuracy. The splicing of pre-mRNAs is conducted by complexes of proteins and RNA molecules called spliceosomes.