AP BIOLOGY

THE MOLECULAR BASIS OF INHERITANCE

STRUCTURE OF NUCLEIC ACIDS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Which technique was used to determine the double-helical structure of DNA?
A
electrophoresis
B
chromatography
C
centrifugation
D
X-ray crystallography
Explanation: 

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: -At King’s College London, Rosalind Franklin obtained images of DNA using X-ray crystallography, an idea first broached by Maurice Wilkins. Franklin’s images allowed James Watson and Francis Crick to create their famous two-strand, or double-helix, model.

Detailed explanation-3: -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-4: -X-ray crystallography is an imaging technique that uses x-ray diffraction to evaluate the molecular structure of a crystalline solid. This article discusses the critical role played by x-ray crystallography in the elucidation of the structure of DNA.

Detailed explanation-5: -Fiber diffraction is a method used to determine the structural information of a molecule by using scattering data from X-rays. Rosalind Franklin used this technique in discovering structural information of DNA. The experiment places a fiber in the trajectory of an X-ray beam at right angle.

There is 1 question to complete.