What are secretions from the stomach lining that contain hydrochloric acid and pepsin?

If a set of instructions that determines all of the charactersitics of an organism is comparedto a book,and a chromosme is compared to chaper in the book,then what might be compared to a paragraph in the book?

What processes take place before the mature mrna exits the nucleus?

At which point is crust neither created nor destroyed? island chain mid-ocean ridge divergent boundary transform boundary