The two hormones that has a close control over the levels of calcium in blood are the parathyroid hormone and the calcitonin.
<u>Explanation:</u>
The calcium ion is one of the most important inorganic ion that is required by the body, this helps in most of the signal mechanisms of the body. The calcium ion is mostly stored in the bones and is needed whenever it is required by the body.
The 2 important hormones such as the parathyroid hormone and the calcitonin act in the opposite directions to regulate this calcium levels in blood.
I'm not sure, we did in class, is to make a blue print of all life and rna is made as well. D NA is double stranded, if this not the answer i can look in my notes.