Deoxyribonucleic acid, often abbreviated to DNA, is found in the nucleus of the cells of almost all living organisms on earth. DNA contains the genetic instructions for making proteins and how an organism will develop, live and reproduce, and is often referred to the building block of life for organisms (reference). DNA is arranged in a spiralling double helix shape, similar to a twisted ladder, and contains thousands of repeating nucleotides, which are the structural components of DNA. Each nucleotide is comprised of a deoxyribose sugar molecule and a phosphate group, which create the backbone of each DNA strand, and a nitrogenous base. There are four bases that can be found within DNA, which include adenine, thymine, cytosine and guanine. These bases form base pairs, where each base will only pair with its complementary base. This means that adenine will only pair with thymine, and cytosine will only pair with guanine. These base pairs make up the rungs of the ladder in DNAs twisted helix formation. The order of the bases within each DNA molecule is what is used as a code to synthesise proteins which determine each characteristic of every living organism. DNA molecules are bound to and coiled around proteins called histones
which allow a large amount of DNA to be stored within each nucleus. These coiled histones form a coiled network named chromatin which, when a cell is about to divide, coils even tighter into structures called chromosomes. This experiment was designed to extract clumped strands of DNA from strawberry cells using a solution of salt, detergent, water and ethanol. The aim of the experiment was to investigate the strands of DNA extracted from the strawberries and analyse the effect that changing the amount of detergent in the solution had on the weight of DNA that was produced from the cells. Strawberries are particularly useful when investigating DNA because they are octoploid, which means that each cell contains 8 copies of each chromosome, resulting in a large quantity of DNA that is able to be extracted in the experiment (Washington). Different quantities of detergent were added to the solutions whilst the amount of strawberries, salt, ethanol and water were controlled in order to test the effect that changing the concentrations of the detergent would have on the amount of DNA produced. The hypothesis of this experiment was that if more detergent was added to the solution, more DNA would be extracted from the strawberry cells.