Final answer:
The body's normal flora is primarily located on the epidermis, which serves as a barrier to water and invasion by pathogens. Gram-positive bacteria prefer dry areas, while Gram-negative bacteria prefer dark and moist areas.
Step-by-step explanation:
The body's normal flora is primarily located on the epidermis, which is the outermost layer of the skin.
The epidermis serves as a barrier to water and invasion by pathogens. It consists of keratin-filled cells and has no blood supply.
Regions of the skin that are dry, such as the forearm, tend to harbor Gram-positive bacteria, while regions that are dark, warm, and moist, such as the underarm or perineum, tend to have a larger percentage of Gram-negative bacteria.