Which best summarizes the scientific process that led to our current understanding of DNA? Each scientist made an important, but unrelated, contribution. Scientists built on the previous work of other scientists to make new discoveries. Most of the discoveries were made by chance and did not depend on prior knowledge. The most important contributions were made within the same time period of the late 1800s.

The best summary is: **Scientists built on the previous work of other scientists to make new discoveries.** ### Explanation: Our current understanding of DNA is the result of cumulative efforts by numerous scientists over many years. Here's a brief overview of how this collaborative process unfolded: 1. **Early Observations:** - **Friedrich Miescher (1869):** Discovered "nuclein" (later known as DNA) in the nuclei of white blood cells. 2. **Structure Elucidation:** - **Rosalind Franklin and Maurice Wilkins (1950s):** Produced critical X-ray diffraction images of DNA, revealing its helical structure. - **James Watson and Francis Crick (1953):** Used Franklin's data, along with other research findings, to propose the double helix structure of DNA. 3. **Genetic Code and Replication:** - **Erwin Chargaff:** Identified base pairing rules (A=T and C=G), which were essential for understanding DNA replication. - **Gregor Mendel's earlier work on genetics** provided foundational knowledge about heredity that informed DNA research. 4. **Advancements in Technology:** - **Development of sequencing technologies** allowed scientists to decode the exact sequence of nucleotides in DNA, leading to the Human Genome Project and modern genetic engineering. Each of these contributions was interconnected, with scientists building upon the discoveries and insights of their predecessors. This collaborative and iterative process is a hallmark of scientific advancement, demonstrating how cumulative knowledge leads to profound understanding.