Valves, they are like flaps of muscle that keeps the blood in its place util its ready to be pumped along.
Answer:
Plants extract the carbon dioxide from the air and use it in photosynthesis process to feed themselves.
Answer: Your answer would be A
Explanation:one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.
False, most of the nutrients are absorbed in our stomach. The intestines are mainly for waste.