DNA

Long stands of double helical DNA can fit into the nucleus of a single cell because DNA is specially packaged through a series of compaction events to fit easily within cell nuclei. Even though the length of DNA per cell is about 100,000 times as long as the cell itself, it only takes up only about 10 percent of the cell’s volume. The DNA molecule, in order to condense, wraps itself around groups of histone proteins, and then the chromatin folds back on it, nucelosomes pack together to create a compact, protein-coated fiber, and the fiber coils to shorten further into an extended chromosome. Finally, the coiled fiber organizes into loops coming from a central axis, creating a condensed, X-shaped chromosome.
2.Why is a sport drink used to collect the cheek cells instead of water? Sports drink which is saline solution contains sodium chloride which makes the solution compatible with osmotic environment of the cells. The sports drink prevents the cells from breaking open and releasing their DNA before they are collected. If water was used, it would be hypotonic to the cells causing them osmosis and eventually burst.
3.What does the cell lysis solution do to the cells’ membranes? It dissolves the phospholipids bilayer of cell membrane by forming water soluble complexes with them

4.How does the DNA in the cell lysate become visible? It becomes visible when ethanol is added. Since DNA is insoluble in ethanol, it cannot be incorporated into the liquids. Ethanol hits the cell lysate which cause the DNA to precipitate out of the solution, forming a cloud of stringy fibers at where ethanol and cell lysate meet.
5.Why can you see the extracted DNA with the naked eye? I can see the extracted DNA with the naked