That would be a Chloroplast
 
        
                    
             
        
        
        
Answer:
The answer is number two extinction happened, this was the time dinosaurs went extinct ebcause lack of sun because oh how much dirt was blown into the earth atmosphere becuase of the asteriod, third option is talking about big bang theroy so that dosnt apply!
Explanation:
 
        
             
        
        
        
1) Pneumothorax in this case; a spontaneous pneumothorax can be life threatening cause the lung will eventually cause vacuum used by the lung to fill with air, and as you constantly expand your lung it decreases and collapses. So C is going to be the answer.
2) Acetylcholine is the hormone responsible for the "Rest and digest". It is the direct opposite of the Fight and Flight reaction which is marked in Bronchodilation, Increased HR, and increased BP. B
3) Secretin is responsible for stimulating the release of bile by the liver. Secretin is released by the duodenum, the junction of the stomach and small intestines. B
        
             
        
        
        
Answer:
The organisms at the base of the food chain are photosynthetic.
Explanation:
 
        
             
        
        
        
Hi!  I can help you out.
RNA polymerase binds to regions of DNA called promoters, which are "start" signals for transcription