Hydroxyapatite is the major component of bone that contributes to its hardness.
Answer:
Pulmonary circulation moves blood between the heart and the lungs. It transports deoxygenated blood to the lungs to absorb oxygen and release carbon dioxide. The oxygenated blood then flows back to the heart. Systemic circulation moves blood between the heart and the rest of the body.
Explanation:
The mRNA made from the section of DNA coding for the protein (the gene) exits the nucleus through a nuclear pore after getting modified. It can get modified by getting a poly-A tail and a methylated cap, along with removing the interfering sequences (introns).
What are the choices?
I'm sure it's a penny.