As a fertalized egg divides, the cells differentiate and become specialized because they? A) have specialized genes activated
B) contain cancer cells
C) contain extra lipids
D) metabolize carbohydrates

Which of the following best describes the purpose of the parathyroid hormone? a. it decreases the blood calcium level and decreases blood phosphorus level. b. it decreases the blood calcium level and increases the blood phosphorus level. c. it increases the blood calcium level and increases blood phosphorus level. d. it increases the blood calcium level and decreases blood phosphorus level.