Describe how the integumentary system responds to differences in sunlight

The integumentary system (skin) reacts different on different sun intensity (different length exposure to sun).

For example, moderate exposure to the sunlight contributes to the production of melanin and vitamin D by the body. On the other hand, high exposure to sunlight can have negative health effects such as sunburn, which is an inflammatory response to DNA damage caused by UV radiation.  

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.

can you give me more to work here with plzs and you