<span>Unidirectional flow in the heart is ensured because the heart contains valves that prevent backflow.
These valves keep the flow of the heart going in one direction (hence the name "unidirectional").</span>
Answer:
Photosynthesis removes carbon from the atmosphere, and cellular respiration releases carbon back into the atmosphere
Explanation:
Answer: No
Explanation: Since when a child is born it has DNA from both. As an example, the mom has brown hair, father has blonde hair, the child would take the DNA for the type of hair they get, either blonde or brown. So since its blood, the fathers is A, and the boy's is B, therefore it didn't take any of their DNA's so nope, he isn't the father.
