The hormone calcitonin, which is produced by the parafollicular or C cells of the thyroid, has the opposite effect on blood calcium levels as does PTH. I hope this helps! : )
Not sure but my best guess is to go with B. It just makes the most sense.
Answer:
all organism evolved on earth, and all are genetically related to one another. Species living under unusual conditions might defer more than others, though. We might also predict that the more similar the percentages of naturally occurring elements are in two species, the more closely related those two species are.
Explanation:
this is what i am assuming the answer could be :)
Answer: B. Closed
In a closed circulatory system is the one in which the blood is circulated to all the parts of the body of the organism through vessels of different length and width. In this system the blood is pumped from the heart through blood vessels where it is transported to different organs and cells of the body instead of filling up the body cavity.
