The structure of the skin is an effective barrier against bacteria. The multiple layers of epidermis, while can be invaded by foreign organisms, has a high turnover rate which means it is constantly shedding, therefore even the bacteria is shed protecting the body. Lastly, the skin's lipids maintain an acidic pH which slows and stops growth and replication of bacteria.
Yes. You could do this by adding solvents to break down any cell walls, centrifuge to separate the DNA, if you haven't got much then upscale with PCR, gel electrophoresis could be used to detect the DNA, and Sanger sequencing to find the sequence.
These would be the elements in row 2 the alkaline metals. Elements in a row usually share many qualities such as electon reactivity as well as similar characteristics like the fact that many alkaline metals are considered Cations, ions with positive charges. Some examples are beryllium and calcium.
Sorry if I’m wrong but I believe it’s the cardiovascular and lymphatic system
Hope this helps!
