Question

Discuss some of the advancements in biology that have occurred as a result of the discovery of the structure DNA and the description of the replication mechanism of DNA. How has Rosalind Franklin's x-ray that helped Watson and Crick to work out the Double helix shape of DNA changed biology and society?

Answer 1

The advancement in biology that have occured as a result of the discovery of the structure of DNA and the replication mechanism of DNA are:-

1)Gene explained -Cracking the structure of DNA explained how the fundamental unit of inheritance -the genes works and how it is replicated from one cell to the next and one generation to the other .It also helps us to understand the molecular basis of gene and how it can be damaged and why mutations can lead to disease or occsionally ,beneficial traits that can form the basis of a new trend in evolution .

2)Predicting inherited disease -Some disorders are caused by genetic defect.Cancer is the classical example .It is caused by acascade of cellular changes triggered by a series of mutations .But sometimes cancer can result from a defect in just one gene that runs in a family such as the breast cancer genes BRAC1 and BRAC2.Thus understanding this lead to the awarness of breast cancer among the society.

3) Human origin ;-DNA analysis supports the fact that early humans originated from Africa less than 100,000 years ago and moved to the different parts of the world .DNA has shown that the farmers migrated west from the Middle East across Europe .DNA test on living people have revealed other ethnic and ancestral origins that have been lost over time .

4)Gene fingerprinting :-Gene fingerprinting enables identification of suspects in case where samples of blood ,semen ,hair etc. have been found .Criminal convictions are made based on this evidences generated by this technique .Thus there is less chances of human error and and through this we can get the most accurate result .

5) Paternity disputes :- In case of paternity disputes ,the DNA structure of the parents and the children is studied and thus provides evidences of family relationship which the individual is inherited from maternl and paternal chromosome.Thus helps in matching the DNA of the actual parents with the children.

6) Human Genome Project :- Through Human Genome Project ,identification of all the approximately 20,000 -25,000 genes is made possible and to determine the sequence of 3 billion chemical base pair that make up human DNA is studied in a human DNA which will result in inventing effective cure  of more complex diseases.

Rosalind Franklin used a technique called X-ray crystallography to find out the 3D shape of molecules .She applied this technique to different samples She made major contribution to the discovery of the shape of DNA . Though this technique she made   'Photo 51' which was an X-ray diffraction image.Her famous image of DNA called 'Photo 51 ' was made using an X-Ray technique that did not require the sample to be in crystal form .She used this method since DNA,like some other big molecules ,does not like to form a crystal.Instead DNA prefers to form organized fibres.Photo 51 still shows the classic diffraction pattern ,but in this case the sample still contained water and was not a crystal .Maurice Wilkins,a colleague of Roselind Franklin had shown this image to Watson and Crick .They made a crucial advantage when they proposed that DNA molcules are made up of two chains of nucleotides paired in such a way to form double helix,like a spiral staircase.This structure announced in their famous paper in April 1953   explained how DNA molecules could replicate itself during cell division enabling the organism to reproduce itself and eventually in 1962 ,James Watson , Francis Crick and Maurice Wilkins  got the Noble prize for the discovery of the shape of DNA .Thus how Roselind Franklin's X-ray helped Watson and Crick to work out the double helix shape of DNA that changed biology and society .