Answer:
An open system is a system that has external interactions. Such interactions can take the form of information, energy, or material transfers into or out of the system boundary, depending on the discipline which defines the concept
Explanation:
 
        
                    
             
        
        
        
Answer:
Myogenic mechanisms
Hormones
Sympathetic nervous system  
Explanation:
Myogenic mechanisms work in the arterioles that serve the glomerulus.
They cause the smooth muscle cells in the arterioles to contract and relax in response to blood pressure changes.
The sympathetic nervous system increases blood flow through the kidneys during resting conditions.
At times of stress, it decreases blood flow through the kidneys, making it more available to the rest of the body.
The hormones angiotensin and aldosterone regulate blood volume by controlling retention of Na⁺ and water.
C is wrong. The parasympathetic nervous system mainly controls visceral organs such as glands.
 
        
             
        
        
        
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<em>Hope this helped, love!</em>
 
        
             
        
        
        
1) They are cold blooded
2) They respire both by Skin and lungs.
3) They lay eggs in water ; they have a 3 chambered heart.
        
                    
             
        
        
        
Not very many, as most would get mauled and eaten by bears and other predators