Cells,tissue,organ organism,organ system
Answer:Mechanical digestion physically breaks down food, like when teeth macerate food into a bolus. The stomach contracts and relaxes in a churning motion. ... Chemical digestion occurs when the bonds within larger food molecules are broken, creating smaller molecules that the body can use.May 30, 2017
Explanation:
Because there always needs to be something that starts it off. Eg: If there was no grass, there would be no animals.
Answer:
During a process called photosynthesis, plants take in carbon dioxide, sunlight ,and water.
Plants make sugar and give off oxygen as a by-product of this process.
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