Chemical digestion involves breaking down the nutrients into smaller cells
Physical digestion is using physical movements such as chewing and swallowing
Controlled burning? I think that's right.
20. The answer is 1 (Precambrian)
21. The answer is 4 (Pennsylvanian)
22. The answer is 2 (Bony Fishes, Dinosaurs, and Mammals)
23. The answer is 2 (Reptiles)
Answer:
Explanation:
pig feeds only because it supplies amino acids necessary to the animal. But of the total amino acids in the diet, only the digestible amino acids are biologically available to the animal
