Answer 
I’m pretty sure it’s all of the above 
Explanation
        
             
        
        
        
Answer:
Fermentation
Explanation:
Fermentation is the process whereby carbohydrates are converted to acohol or acid by the activities of some enzymes. During the process of fermentation, carbon dioxide is produced and it is found as tiny pockets of air inside the bread dough. This make it to rise. The alcohol produced evaporates later during the bread making process.
 
        
             
        
        
        
Answer:
Eventually, the environment will be unable to support the production of wildebeests, this will cause there to be a loss of vegitation that then causes a food shortage, and then the wildebeests will starve.  
Explanation:
It's a very unhappy process, but those herds who don't migrate to another pasture will starve and die. The death will depopulate the savanna and give the fields some time for regrowth and the cycle will begin again. 
Hope this helps! :)