Essential nutrients are made inside our body.
A. true
B. false

As you sit in the library with your friend studying for your weekly quiz on the integumentary system, you come upon an article about the hazards of prolonged exposure to the sun's rays. your curious nature leads you to research the subject further. you're fascinated to learn that minimal exposure to the sun allows you skin to manufacture vitamin d, which is important to maintain homeostasis. you also read that although sunscreen can protect you from the ultraviolet (uv) rays of the sun, some medications can actually increase a person's sensitivity to the sunlight.

During the first month of development, how many layers of cells make up the embryo? a. 1 b. 2 c. 3 d. 4

What should you not do when doing abdominal workouts? a. keep your chin off your chest b. keep your head aligned with the spine c. put pressure on your neck d. all of the above