The statement above is false. The blood levels of calcium is regulated by parathyroid hormone.When one is not getting adequate calcium in one's diet and the blood level of calcium is low, the parathyroid hormone will be released. The parathyroid hormone can increase the blood calcium in several ways:
1. by stimulating osteoclasts which break down bone and release calcium into the blood stream.
2. by increasing the amount of calcium re-absorbed by the kidney before it can be excreted in urine.
3. by triggering the formation of calcitriol which increases the absorption of dietary calcium at the  intestines.
        
             
        
        
        
Answer:
Yes
Explanation:
I say yes because with the Earth's "sunscreen" layer waring down, the heat of the sun; even if the hole was in the north pole, could overheat the earth causing a change in all environments including the desert.
 
        
             
        
        
        
Gtc atc gca this should be correct because guanain pairs with cytocine and thymine pairs with adnine
        
             
        
        
        
Answer:
This is allopatric speciation. The organisms were separated from each other by the containers. The separation caused them to evolve to the point that they were more likely to mate with each other than with a member of another tank.
Explanation:
 
        
             
        
        
        
A, because it the constant variable