Answer:
calcitonin
Explanation:
Calcitonin is a hormone which helps in lowering the high blood calcium levels. It is secreted by thyroid glands. Parathyroid glands are responsible for increasing calcium level in the blood while calcitonin hormone work against parathyroid glands and helps in lowering calcium level. Calcitonin hormone inhibit the activity of osteoclasts which are responsible for releasing of calcium from bones into the blood.
Answer:
D) Can simple organic molecules form spontaneously in an oxygen-free atmosphere?
Explanation:
Cells are what make up organisms. Cells make tissues, tissues make organs, organs make systems, and organ systems make organisms.
Blocks, Since water blocks sunlight, photosynthesis can't occur in deep waters, because sunlight is required for photosynthesis.
