Answer:
Most pre-mRNA molecules have sections that are removed from the molecule, called introns, and sections that are linked or together to make the final mRNA, called exons.
This procedure is called In Vitro Fertilization (IVF)
The three main worm phyla are flatworms, roundworms, and segmented worms. Roundworms have a digestive tube that has two openings. Segmented worms have a closed circulatory system in which blood is enclosed in blood vessels. These are important steps in the evolutionary development of animals.
Answer: It is a technique used to amplify a segment of DNA of interest or produce lots and lots of copies. In other words, PCR enables you to produce millions of copies of a specific DNA sequence from an initially small sample – sometimes even a single copy. (looked it up on google lol)