Answer:
The kidneys take of up more Ca2+ and release vitamin D. The bones release Ca2+. The intestines increase reabsorption of Ca2+.
 
        
             
        
        
        
Answer:
A
Explanation:
Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. The size and coding capacity of the mitochondrial DNA varies considerably in different organisms, and encodes rRNAs, tRNAs and essential mitochondrial proteins.
 
        
             
        
        
        
Answer:
Axon
Explanation:
A neuron has three main parts. The cell body directs all activities of the neuron. Dendrites extend out from the cell body and receive messages from other nerve cells. An axon is a long single fiber that transmits messages from the cell body to the dendrites of other neurons or to other body tissues, such as muscles. 
 
        
             
        
        
        
Ten (10%). when an animal eats the plant, 10% of it will be used.