Answer:
Chloroplasts are endosymbiotic descendants of photosynthetic cyanobacteria-like prokaryotes that were incorporated into cells more than a billion years ago.
Explanation:
Photosynthesis converts electrochemical energy from light into sugars and acts as the carbon source of the cell.
Animal action is physical weathering
<span>Pepsin is an enzyme that breaks down proteins into amino acids in the stomach (where the pH is 1-3). Pepsin needs to be in an acidic environment to be activated. The optimum temperature is between 30 oC and 40 oC because the average human body temperature is 37 oC. The optimum pH is the acidic one because your stomach has an acidic pH.</span>