Which statement about the difference between autotrophs and heterotrophs is true?
a. autotrophs transform radiant energy into chemical energy, but heterotrophs can’t.
b. autotrophs take in only oxygen, but heterotrophs take in both oxygen and carbon dioxide.
c. autotrophs have two different electron transport systems, but heterotrophs have none.
d. autotrophs don’t have a calvin cycle, but heterotrophs do.
when you swallow food, it doesn't just drop down into your stomach. muscles contract in a wave-like motion to move the food along through the esophagus. this muscle movement is called, peristalsis, or peristaltic waves. these peristaltic waves contract behind the food bolus pushing it along the digestive tract.