scroll to top
Stuck on your essay?
Get ideas from this essay and see how your work stacks up
Word Count: 1,845
DNA The MakingLyle SykesFor more than 50 years after the science of genetics was established and the patterns ofinheritance through genes were clarified the largest questions remained unanswered Howare the chromosomes and their genes copied so exactly from cell to cell and how do theydirect the structure and behavior of living things This paper will discuss thosequestions and the people that answered themTwo American geneticists George Wells Beadle and Edward Lawrie Tatum provided one of thefirst important clues in the early 1940s Working with the fungi Neurospora andPenicillium they found that genes direct the formation of enzymes through the unitsof which they are composed Annas 1996 Each unit a polypeptide is produced by aspecific gene This work launched studies into the chemical nature of the gene and helpedto establish the field of molecular geneticsThe fact that chromosomes were almost entirely composed of two kinds of chemicalsubstances protein and nucleic acids had long been known Partly because of the closerelationship established between genes and enzymes which are proteins protein at firstseemed the fundamental substance that determined heredity Goetinck 1995 In1944 however the Canadian bacteriologist Oswald Theodore Avery proved thatdeoxyribonucleic acid DNA performed this role He extracted DNA from one strain ofbacteria and introduced it into another strain The second strain not only acquiredcharacteristics of the first but passed them on to subsequent generations By this timeDNA was known to be made up of substances called nucleotides Each nucleotide consists ofa phosphate a sugar known as deoxyribose and any one of four nitrogen-containing basesThe four nitrogen bases are adenine A thymine T guanine G and cytosineCCaldwell 1996In 1953 putting together the accumulated chemical knowledge geneticists JamesDewey Watson of the US and Francis Harry Compton Crick of Great Britain worked out thestructure of DNA This knowledge immediately provided the means of understanding howhereditary information is copied Watson and Crick found that the DNA molecule is composedof two long strands in the form of a double helix somewhat resembling
@Kibin is a lifesaver for my essay right now!!
- Sandra Slivka, student @ UC Berkeley
Wow, this is the best essay help I've ever received!
- Camvu Pham, student @ U of M
If I'd known about @Kibin in college, I would have gotten much more sleep
- Jen Soust, alumni @ UCLA