Which of these levels of biological organization contains the other three? A. Organ
B. Organ system
C. Tissue
D. Cell

Alaska and northern canada have a diet rich in vitamin d and their skin color is darker than predicted on the basis of iv intensity at their latitude. explain the observation:

Parasitism could be considered a form of which of these types of relationships? -mutualism -commensalism -predator-prey -mimicry

Which layer will become saturated first when rain falls?