B. I, II, III
Mollusks have 3-chambered heat. They have gills and they have 1-way digestion.
Other characteristics of mollusks are:
1) Bilaterally symmetrical
2) Body has more than two cell layers, tissues and organs
3) body without cavity
4) body monomeric and highly variable in form, may possess a dorsal or lateral shells of protein and calcarous spicules.
5) has a nervous system with a circum-oesophagal ring, ganglia and paired nerve chords
6) has an open circulatory system with heart and aorta
7) has a pair of kidneys
8) reproduction normally sexual and gonochoristic
9) feed a wide range of material
10) live in most environment
Answer:
Calcitonin- reduce blood calcium level
Parathyroid hormone- Raise blood calcium level
Explanation:
The thyroid gland is an endocrine gland which secrete its hormone in the blood directly. Both calcitonin and parathyroid hormone are released by the thyroid gland. Parathyroid hormone is released when the blood calcium level is low.
Parathyroid hormone increases the blood calcium level by osteoclast stimulation which releases calcium from bones and increases blood calcium level. Calcitonin is antagonistic to parathyroid hormone and it reduce the blood calcium level in the blood by stimulating the activity of osteoblast.
People can be dehydrated and if the world water runs out the human population can decrease easily. (Answer my question too plz)
<h2>The answer is:</h2>
Expansion and cracking
<h2>Explanation:</h2>
Whenever water freezes, it is expanded about 9 percent. Since the water in moist concrete freezes it producing pressure in the pores of the concrete. The collective effect of freeze-thaw cycles and disruption of aggregate can eventually cause expansion and cracking, scaling, and crumbling of the concrete that is formed from moist.
