When was DNA discovered as a major chemical of the nucleus of the cell according to the material?

When was DNA discovered as a major chemical of the nucleus of the cell according to the material?

• A. 1865
• B. 1900
• C. 1953
• D. 1905

Answer: (A)

The main idea here is recognizing when scientists first identified DNA as a major component of the cell nucleus. In the late 1860s, Friedrich Miescher isolated a substance from the nuclei of cells and called it nuclein, the precursor to what we now call nucleic acids. This work showed that the nucleus contains a distinct chemical, laying the foundation for DNA’s role in heredity. The widely cited historical date for this landmark discovery is in the late 1860s, with 1869 often referenced; some sources may list an earlier year due to different interpretations or publications, but the essential point is that the nucleus houses a unique nucleic substance discovered in that period. This discovery set the stage for later work establishing DNA as the genetic material and, much later, its molecular structure.

The main idea here is recognizing when scientists first identified DNA as a major component of the cell nucleus. In the late 1860s, Friedrich Miescher isolated a substance from the nuclei of cells and called it nuclein, the precursor to what we now call nucleic acids. This work showed that the nucleus contains a distinct chemical, laying the foundation for DNA’s role in heredity. The widely cited historical date for this landmark discovery is in the late 1860s, with 1869 often referenced; some sources may list an earlier year due to different interpretations or publications, but the essential point is that the nucleus houses a unique nucleic substance discovered in that period. This discovery set the stage for later work establishing DNA as the genetic material and, much later, its molecular structure.