Simplify the following text for a Grade 9 native English-speaking person.
Original: Much of the work in molecular biology is quantitative , and recently much work has been done at the interface of molecular biology and computer science in bioinformatics and computational biology . As of the early 2000s , the study of gene structure and function , molecular genetics , has been among the most prominent sub-field of molecular biology .
Simplified: Molecular biology is the study of biology at a molecular level .