Its the second option....................................... :)
Your body needs two key nutrients: calcium and vitamin D. Calcium is the mineral that strengthens bones and teeth, and vitamin D helps the body absorb calcium while improving bone growth. So stuff like <em>yogurt, milk, salmon, tuna, and spinach.</em>
Answer: Plants are cloned to produce identical plants quickly and economically.
Answer: Cells typically receive signals in chemical form via various signaling molecules.