1. Above: DNA in test tube, Cheek DNA stained and after water (no change) , and cheek DNA after membrane disruption
2. I think the first photo ( DNA in the test tube) would be the most useful in extracting the DNA because your have already broken it apart from the cell, and can clearly identify the strands. Although the second method using the stained cells would be quicker and easier, I believe that using the DNA in the test tube will provide the most quality results as you see more in detail how it looks and works without having it stained.
3. Personally, the second lab was the most interesting as it required more skill and use of common scientific machinery. I have only used a microscope a handful of times before, so it was quite a interesting and fun experience to be able to see individual cells up close and be able to notice every detail and how different substances affect the life and growth of the cells. Finally, the second lab provided a more in-depth experience, as being able to break down the parts of the cell and identify how they work using just your eyesight and a lens.
Raihan