No one knew how heredity (inheritance traits) worked until Gregor Mendel, an Austrian monk, crossed pea plants in the vegetable garden of his monastery in 1865. In 1869, gene-hunters found a rod-like shape in the nucleus of cells that turned red when a dye was added. They called this "Chromosome", from a Greek word, chroma for color. They also looked deeper into the cell and discovered a wispy microscopic thread inside the chromosomes, which they called DNA. Several scientists were unaware of Mendel's breakthrough at the time, but in 1900 they rediscovered his experiment and old newspaper copies. Francis Crick (American) and James D. Watson (English) had a problem with DNA (deoxyribonucleic acid). ) in 1950 because the individual parts were not visible. They could be observed by X-ray crystallography, carried out at Kings College London. They were convinced that DNA was a double-helical spiral ladder containing two to four chemical strands. It consisted of two intertwined strands. The DNA was cracked! They solved the three-dimensional structure of DNA in Cambridge, England, and were ready to show the first model to their colleagues on March 7, 1953. They learned how genes worked and how inherited characteristics were passed down from one generation to the other. Their discovery was included in Matt Ridley's book Genome. People knew that heredity also affected animals and plants, just like humans. Having red hair or blue eyes is passed down from generation to generation. Watson met the head of the King's College team, Maurice Wilkins, who worked closely with Rosalind Franklin. Rosalind Franklin, a British biophysicist, is the person who discovered the structure of DNA using X-ray crystals...... middle of paper ......s/dna_timeline/97/3 . http://answers.yahoo.com/question/index?qid=20080107200905AAl6RyT4. http://www.cancerresearchuk.org/cancer-help/about-cancer/cancer-questions/what-is-dna-what-does-it-stand-for5. http://en.wikipedia.org/wiki/James_Watson6. http://en.wikipedia.org/wiki/Francis_Crick7. http://en.wikipedia.org/wiki/Heredity8. http://en.wikipedia.org/wiki/Rosalind_Franklin9. http://ghr.nlm.nih.gov/handbook/basics/dna10. https://www.genome.gov/2552088011. http://www.statedclearly.com/12. https://www.23andme.com/gen101/genes/13. http://seedmagazine.com/images/uploads/12Cribsheet.pdf14. http://ca.answers.yahoo.com/question/index?qid=20081218195035AASs8Tw15. https://s3.amazonaws.com/engrade-myfiles/4093573902791905/Chromosome_diagram.png16. http://www.sciencedaily.com/releases/2011/07/110721142408.htm?utm_medium=twitter&utm_source=twitterfeed