<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:
Water pollution is known to be a growing problem of 21st century all over the world. As a result of water pollution, pure water is transferred to less scare day by day. The most unique advantage of aquatic environment is the existence of life, and the most special feature of life is its biodiversity. There are many reasons for water pollution that affected negatively biodiversity. The planet’s biological diversity is affected greatly by any human activity. Six threats affect aquatic biodiversity; climate change, overexploitation, water pollution, habitat degradation, flow modification and exotic species invasion. Biodiversity maintenance is considered one of the leading keys to ecosystem services retention. So it can be said that the ultimate challenge nowadays is the protection of freshwater biodiversity.
Explanation:
The offspring copies 50% from the mother and 50% from the father genes mostly. But along the process of cell cycle their are changes will undergone and the percentage will vary.
