It's purpose is to break down energy from carbohydrates and other organic molecules stored during photosynthesis 
        
             
        
        
        
<h2>540 million years ago
</h2>
Paleozoic.
Era immediately follows Precambrian It lasted about 4.5 billion years.
When did abundant fossil evidence first appear in the geologic record.
540 million years ago.
 
        
        
        
2 would be A because fertilization is where the sperm cell and egg unite. 3 would be C because in the picture you can see how the division is occuring.