Which gland secretes the most important hormone controlling calcium balance in the blood?

The Parathyroid gland

Explanation:

The Parathyroid gland secretes "Parathormone", an hormone that exerts

- direct influence on the bone by INCREASING the release of bone calcium ion (Ca2+) into the blood

- affects the kidney by stimulating the renal tubules to eliminate EXCESS calcium in the urine.

Thus, the calcium balance of the body depends on the secretion of the Parathyroid gland

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.

clumped distribution, because you'de have all of the population gathered in a relatively small are.

it's the most common because it provides protection and a mate for reproduction

example: humans, seeweed, cattles, etc.