1.     (a) Listing What are five important functions of the skin?

(b) Identifying How does the epidermis protect the body? What structure in the dermis helps to maintain body temperature?

(c) Inferring What could happen if the pores in your dermis become blocked?

2.     (a) Identifying What are three things you can do to keep your skin healthy?

(b) Explaining Why is it important to use sunscreen to protect your skin when outside?

(c) Making Judgements Do you think it is possible to wash your skin too much and damage it as a result? Why or why not?

Sunscreen Ratings

The graph shows how sunscreens with different sun protection factor (SPF) ratings extend the time three people can stay in the sun without beginning to get a sunburn.

(1) Reading Graphs What does the height of each bar in the graph represent?

(2) Interpreting Data How long can Person B stay in the sun without sunscreen before starting to burn? With a sunscreen of SPF 4? SPF 15?

(3) Inferring Suppose that Person C was planning to attend an all-day picnic. Which sunscreen should Person C apply? Use data to support your answer.

(4) Calculating Which is more effective at preventing sunburn—a sunscreen with SPF 4 or one with SPF 15? How much more effective is it? Show your work.

(5) Drawing Conclusions What does the number in the SPF rating stand for? (Hint: Note the length of time each person can stay in the sun without sunscreen and compare this value to the length of time each can stay in the sun using SPF 4. Then, do the same for SPF 15.)