<span>Norepinephrine uses the Second
Messenger System, which means, cells signal to each other what molecules have
been released that will trigger a physiological reaction. </span>
<span>
This phenomenon is activated after the ligand  (ion or molecule) is bonded to its receptor
(protein molecule), creating a variation that causes a chain-reaction, that will
finally activate the Second Messenger. The latter will activate intercellular
molecules that will be able to control the cell’s activity. </span>
 
        
             
        
        
        
 The phenomenon is called an equinox. More specifically when it is September it is called the autumnal equinox ,and when it is March it is called the vernal equinox.  Hope this helped!
 
        
             
        
        
        
Answer:
Yes, vaccination should be mandatory because without it all of us would slowly died from not having a cure. According to research people, they said; "vaccination will helps you to stay healthy. It also are important to your overall health such as diet and exercise."
Explanation:
 
        
             
        
        
        
Let,
Dominant trait, red color be designated as C'C'
Recessive trait, white color be represented as C"C"
The F₁ generation of the cross : 
C'C'  X C"C" = C'C"
F₂ generation cross is shown in the image attached.
According to the cross, the probability of pink flower being produces 1s 50%
 
        
             
        
        
        
A type of commensalism is the sea anemone and the clown fish. The definition of commensalism is where another species lives within another. (Usually this relationship is with animals, fungi, and plants.) No harm comes to either species. 
A clown fish lives in a sea anemone, and this doesn't hurt the anemone nor is the clownfish affected by its sting because of their oils that protect them.
If you didn't know, Nemo and his father, Marlin, lives in a sea anemone. A natural habitat of a clown fish.