Vitamin d is unique in that it can be obtained by the diet but also is synthesized inside the body when a cholesterol-like substance is activated by sunlight and converted to the prohormone vitamin d. check all of the organs that participate in vitamin d synthesis and activation.

The earth's polarity has switched many times through history as evidence by what wh the earth clorets he has switched many times throughout history as evidence by what

Which pair of sentences is describing the same velocity? a. a car is parked. a car is moving in circles. b. a bus drives 40 miles per hour north. a truck drives 50 miles per hour north. c. a boy walks east at 6 kilometers per hour. a girl walks west at the same speed as the boy. d. valerie rides her bike south at 8 kilometers per hour. owen jogs south at 8 kilometers per hour.

which is an effect of short-term environmental changes? a) adaptation b) speciation c) extinction d) death (5 points)