The correct answer is: introns
Processing of mRNA is process that occurs only in eukaryotic cells. After the transcription, newly formed mRNA molecule is called and it must be processed into a messenger RNA (mRNA). Processing includes:
• Addition of a 5' cap to the beginning of the RNA
• Polyadenilation- addition of a poly-A tail (tail of A nucleotides) to the end of the RNA
• Splicing- removal of introns and linking the exons
After these steps mRNA is mature and used for the further steps (e.g. translation).
Sometimes some genes are alternatively spliced.
Cells divide for many reasons. For example, when you skin your knee, cells divide to replace old, dead, or damaged cells. ... When organisms grow, it isn't because cells are getting larger. Organisms grow because cells are dividing to produce more and more cells.
the picture print is not good enough to be readable please delete the question and post a new question wth a good print