AP BIOLOGY

Detailed explanation-1: -Created by Rosalind Franklin using a technique called X-ray crystallography, it revealed the helical shape of the DNA molecule. Watson and Crick realized that DNA was made up of two chains of nucleotide pairs that encode the genetic information for all living things.

Detailed explanation-2: -British scientist Rosalind Franklin’s application of radiation science was truly historic. Her work with x-ray crystallography confirmed the double-helix structure of the DNA molecule.

Detailed explanation-3: -Rosalind Franklin discovered the density of DNA and, more importantly, established that the molecule existed in a helical conformation. Her work to make clearer X-ray patterns of DNA molecules laid the foundation for James Watson and Francis Crick’s suggestion that DNA is a double-helix polymer in 1953.

Detailed explanation-4: -Crystals are solids with regular, repeating units of atoms. Some biological macromolecules, such as DNA, can form fibers suitable for analysis using X-ray crystallography because their solid forms consist of atoms arranged in a regular pattern.

Detailed explanation-5: -Rosalind Franklin and Raymond Gosling obtained this X-ray diffraction pattern, which triggered the idea that DNA was a helix.