Read the passage about an athlete.

when an athlete's body temperature begins to climb, blood vessels in the skin dilate. as a result, the athlete's face turns red because warm, oxygenated blood moves to the surface of the skin. this process to reduce overall body temperature and prevent overheating.
which organ system most likely to keep an athlete from overheating?

a
the digestive system

b
the circulatory system

c
the respiratory system

d
the reproductive system

The model illustrates a process by which a substance is taken up by a cell

When in solution, a molecule that moves slowly across an artificial membrane moves rapidly across a plasma membrane. this molecule rapidly enters the cell regardless of whether its concentration is higher inside or outside the cell. using this information, which transport mechanism is most likely to be responsible for the movement of the molecule across a plasma membrane? view available hint(s)when in solution, a molecule that moves slowly across an artificial membrane moves rapidly across a plasma membrane. this molecule rapidly enters the cell regardless of whether its concentration is higher inside or outside the cell. using this information, which transport mechanism is most likely to be responsible for the movement of the molecule across a plasma membrane? active transportexocytosis

Using meiosis, the sporophyte produces spores that are .