Molecular biology is the branch of science that focuses on the structure and function of the molecules that make up living organisms. It primarily studies DNA, RNA, and proteins, which are essential for processes like gene expression and cellular function. By understanding these molecules, scientists can learn how traits are inherited and how cells communicate. This field combines techniques from genetics, biochemistry, and cell biology to explore how biological systems operate at a molecular level. Discoveries in molecular biology have led to advancements in medicine, such as the development of targeted therapies and gene editing technologies like CRISPR.